The alphabetical letters (consonants) are merely symbols of sound. No doubt the words are formed by placing the consonants together, but they cannot be pronounced until some proper vocalization/vowelization system (diacritical marks) be applied. Some scripts and languages have introduced vowels in their alphabet to meet this requirement, but they are not sufficient and their scope is limited. Subtle differences of pronunciation cannot be expressed through them. Therefore some languages had to evolve their own systems of vowel/diacritical signs and Arabic is almost the foremost instance of it. Hebrew was void of any vowel/diacritical signs until seventh century AD. Sir Frederic Kenyon writes:
(…) In its original state only the consonants were written, the vowels being left to be filled up by the reader's mind. (…). This ancient practice of omitting the vowels is one fertile cause of varieties in the text, for it will readily be understood that doubts might often occur as to the proper vowels to be supplied to a group of consonants. To take a parallel from English, the consonants 'M R' might be read as mare, mire, or more [or mur (as in murmur), or mere, or mar, etc], and it is quite possible that in some cases the sense of the passage would not show for certain which way was right.
Shemaryahu Talmon, Professor of Bible, The Hebrew University of Jerusalem writes:
The absence of vowels meant that many a Hebrew consonant group could be differently pronounced, and from this resulted the fact that a variety of meanings could be attached to one and the same word in the original. When ultimately vowels were introduced into the Hebrew text of the Bible, these pronunciation variants sometimes became the bases of variae lections (various readings).
The language of the OT was mostly Hebrew. It cannot be determined of certain when its script came into existence. David Diringer, formerly Reader in Semitic Epigraphy, Cambridge University, says:
Through the results of excavation and research, the development of the early Hebrew alphabet can now be traced for more than a thousand years. We may assume that about 1000 BC, after the United Kingdom had been established and its centralized administration organized by King David with a staff of secretaries (see, for instance, 2Sam. 8:17 and 20:25), the early Hebrew alphabet had begun its autonomous development.
It took early Hebrew alphabet almost one thousand years to evolve into the modern square Hebrew alphabet. The same writer explains:
The (square) Hebrew alphabet became standardized just before the Christian era and took the form which, with insignificant changes, we have now.
For centuries the Hebrew script remained restricted to groups of letters placed together and vowel signs were not introduced to it. The same writer explains:
The Hebrew alphabet consists of the ancient 22 Semitic letters, which are all consonants, though four of them (aliph, he, waw and yod) are also used to represent long vowels, particularly at the end of a word. The absence of vowel letters was not very strongly felt in Hebrew any more than it was in the other Semitic languages (Indeed, it must be emphasized that the Semitic languages are mainly based on consonantal roots). On the other hand, as Hebrew speech passed out of daily use, and familiarity with Biblical Hebrew steadily declined, it became necessary to introduce some form of vocal distinction, so that the Torah could be read and explained correctly.
When, in the second half of the sixth century (ca 529) BC, Cyrus of Persia conquered Babylonia and, terminating the exile of the Jewish people, allowed them to leave Babylonia and to go back to their homeland, Jerusalem; two separate centers of learning evolved among Jews: Babylonian and Palestinian. Vocalization/diacritical signs were developed there during the late fifth to ninth century AD. In the eighth century, refinements were introduced into the vocalization which ultimately produced the complicated scheme of supralineal pointing. Rev. Prof. B. J. Roberts, Prof. of Hebrew and Biblical Studies, Univ. College of North Wales explains it in his article 'The OT, MSS, Text and Versions' as follows:
The survival of the two main traditions of Massoretic activity in Babylon and Palestine is seen in the two divergent Massoroth, (…). Nowhere is the divergence more obvious or more relevant than in the systems of vocalization which were superimposed on the consonantal text and which were developed both in Palestine and Babylon between the late fifth century and the ninth century A.D. In Babylon sporadic use of vocalic consonants and dots was made to assist and to formalize the correct recitation of the hitherto unvocalized, consonantal text in synagogue worship. In the eighth century, (…), refinements were introduced into the vocalization which ultimately produced the complicated scheme of supralineal pointing which still survives in the so-called Babylonian vocalization. (…).
The earlier, primitive phases of the vocalization in both transmissions are almost wholly unknown, except for incidental and until recently incomprehensible references in late rabbinic works, (…).
It requires a lengthy discussion. Only a brief background of the theme has been afforded here, which explains that the attempts of recording the exact pronunciation of some Hebrew word succeeded after the Islamic era; hundreds and in some cases thousands of years after the claimed origin of those books. How is it possible that correct pronunciation of the words of the Bible could have been properly preserved without the existence of any system of diacritical signs or vocalization? The Biblical scholars could not fix the pronunciation of even the name of their God: 'YHWH'.
Geddes MacGregor writes:
Not even the most perfect copyist could ensure an unambiguous text, for Hebrew was written entirely without vowels, which the reader had to supply for himself. (…). Competent Hebraists, without as much difficulty as one might suppose, read manuscripts written in this way; but ambiguities were inevitable. To help in the elimination of these ambiguities, a school of Jewish scholars, the Massoretes, invented, probably about the sixth century A.D, a system of pointing —dots and dashes placed under the Hebrew letters to indicate the vowel sounds. The Massoretes naturally vocalized the text according to the practice of their own day. From this Massoretic text, in 'pointed' Hebrew, we can know fairly well how Hebrew sounded when it was solemnly chanted in a synagogue as long ago as, say, the time of Mohammed. But we have no such clear knowledge of how it may have been pronounced by David or Solomon. The Massoretes halted the corruption that the passage of centuries had inevitably introduced; but they came on the scene much too late to preserve for us an entirely pure unambiguous Old Testament text. They also compiled a set of notes, called Massorah, and offered variant readings.
(…) about the end of the first century A.D., (…), there were considerable textual variations among the existing manuscripts. The problem of later determining what, in a doubtful case, was the original reading, is obviously a difficult and highly technical one demanding, for its solution, great learning and skill. (…). If we remember that besides such textual disparities there are also, in unpointed Hebrew, great possibilities of ambiguity, and that the Massoretes themselves frequently misled posterity by faulty vocalization that changed the meaning, we shall have some notion of the complexity of the task of trying to recover, as far as may be possible, the original Old Testament text.
Unger has touched the subject briefly but lucidly in the following words:
Before A.D. 500 Hebrew manuscripts had no system of vowel indication, except certain consonants to indicate long vowels. Between A.D. 600 and 950 Jewish scholars, called Masoretes (Traditionalists), invented a full system of vowels and accents to punctuate the text. They also standardized the text, including marginal readings (called keri) and textual variants (called kethiv).
The Jewish Enc. has explained it in the following words:
All Semitic script, (…), is purely consonantal, the reader being left to supply the vowels. (…). To obviate such ambiguity the Semitic languages have developed three methods. The oldest method is to denote the vowels by the vowel-letters אוי(a, o, y). (…). But since the vowel-letters were not sufficient to mark the exact shades of the vowel-sounds, some of the Semitic languages (i.e. those which were in possession of sacred books in whose recitation exactness was imperative) developed systems of vowel-signs. (….). Elijah Levita had already pointed out that the Talmudim and Midrashim do not mention vowel-signs or vowel-names, in spite of there having been abundant opportunity to do so. From this fact he concluded that vocalization and accentuation are post-Talmudic. The earliest dated mention of vocalization is that of Saadia Gaon and his contemporaries. Between the dates 500 and 900 the following data are to be considered: Even Aaron ben Moses ben Asher, whose ancestor in the sixth generation flourished in the second half of the eighth century, was ignorant of the origin of the vowel-points. A still older authority than Ben Asher the elder, R. Phinehas, the head of the academy, is quoted as authority for T (Tiberian system of vocalization). (…). He (R. Phinehas) must have lived early in the eighth century, or must have been contemporary with Khalil Ibn Ahmad (719-729[? 786]), to whom the introduction of the Arabic system is attributed. Assuming that A (Arabic system of vocalization) and T (Tiberian system) were introduced about 750, these being based on P (Palestinian system) and B (Babylonian), the date for P must be about 700, (…).
John Frederick Stunning, Univ. Reader in Aramaic, Oxford, Writes in his article 'The Texts and Versions' [of the OT]:
The form in which the Hebrew text of the OT is presented to us in all mss. and printed editions is that of the Masoretic text, the date of which is usually placed somewhere between the 6th and 8th centuries [AD](….). Their [Masoretes'] work may be said to culminate in the vocalized text which resulted from the labours of Rabbi Aaron ben Asher in the 10th century. (….). It is, however, certain that before the 2nd century AD the various mss of the OT differed very materially from one another. (…). Indications are also not wanting in the Hebrew text to show that in earlier times the text was treated with considerable freedom. (….). At the same time it is clear both from internal and external evidence that the archetypefrom which our mss are descended was far from being a perfect representative of the original text. For a comparison of the different parallel passages which occur in the OT (e.g. I & II Sam., (…), etc.) reveals many variations which are obviously due to textual corruption.
Enc Americana has also afforded an account of the vocalization of the Biblical text. It would be very useful to go through it because it has dealt with the theme in a brief and systematic manner. The writer of the article 'MSS and Versions of the OT', Arthur Jeffery of the Columbia University states:
As certain documents, however, came to be regarded as something apart, something of importance for the religious life of the community, there arose among the Jews, (…), those who devoted themselves in a particular way to the care of such writings. These later were called Sopherim, and although this is popularly translated 'scribes', they were not merely copyists, but keepers of records, interpreters, and 'bookmen' in widest sense. (….). It was by their labors that the text was standardized for transmission, and in that process of standardization, as reverence for Scripture increased, they, from motive of piety, introduced little alterations [what an interesting use of piety: to introduce changes in the divine revelation!], safeguarding the divine name, disfiguring the names of heathen deities, replacing indelicate or unseemly expressions by euphemisms, emending passages likely to be misunderstood, and at times modernizing the language. The evidence of all this is in the text as they have transmitted it to us.
The period of the early Sopherim may be considered to have extended from about 500 B.C.to 100 A.D. From the closing of the Palestinian Canon about 100 A.D. to about 500 A.D. is the period of later Sopherim. Part of the activity associated with the closing of the canon was concerned with the question of a standard exemplar of the text. This would seem to have been settled by the labors of the School of Rabbi Akiba (died 135), (…).
The Sopherim were succeeded by the Masoretes, whose labors extended from about 500 A.D.to the invention of printing. The early text left by the Sopherim was for the most part a purely consonantal text with no pointing for vocalization or accentuation, no punctuation in our sense, and with little more to help the reader than some breaking up of the text into paragraphs. The Masoretes labored to supply the text with these elements that were lacking and in addition compiled a great body of annotations, some statistical, some text-critical, some exegetical, all with the twofold purpose of safeguarding the text and making it fully intelligible to the reader. They standardized a system of verse division, and broke up the text into pericopesof convenient size of liturgical cycles of public reading of the Scriptures. Three systems of vocalization worked out by them are known, a Babylonian, a Palestinian, and a Tiberian, the latter of which is found in most manuscripts and the printed texts. There are also three systems of accentuation. The vocalization consists of little signs written below, within, or above the consonants to indicate correct pronunciation. (…). There were schools of Masoretes, but it was the Tiberian School that finally came to dominate textual studies, so that most Hebrew manuscripts of the Old Testament derive from the famous tenth century Tiberian Codices of Ben Asher and Ben Nephtali. 
Enc. Judaica has also recorded an article on this theme. Some of its excerpts are afforded below:
5. VOCALIZATION AND ACCENTUATION
There are three graphic systems of vocalization and accentuation for Hebrew: 'Palestinian', 'Babylonian', and 'Tiberian'. (…).
The Tiberian system is the most sophisticated and complete in the items which it transmits; and it is the most recent. Most scholars tend to believe that the Palestinian is the older of the other two systems. However, since these two systems developed in different countries, Babylonia and Palestine, and since at the beginning of their development there was no contact between them, and since the signs differ in the two systems (letters and dots), it is impossible to arrive at a definite decision in this question on the basis of the data available today. In line with the generally accepted opinion the Palestinian system is discussed first; however, this is not meant to indicate a view on the relative dating of the systems.
The Palestinian System
The State of Transmission
The Palestinian is not a crystallized system. Almost every one of the manuscripts has a number of individual and characteristic traits with regard to the use of signs. It is possible to point to the common and similar aspects but not to all the deviations of each manuscript. For what we find in the manuscripts is actually a system in development. Scholars endeavor to fix the date of a text on the basis of the degree of progress shown by the use of the signs in it: the oldest manuscripts (apparently from the eighth century) have generally very few signs, sometimes no more than one or two for a word and sometimes not even that; and even the latest of them never reach the stage of fully marking each vowel and its nuances, as is the case in the Tiberian system. (….).
The Babylonian System
This system was called Babylonian in accordance with references by a number of early scholars.
The Tiberian System
The Vowel Signs
Unlike its predecessors, the Tiberian vocalization has reached us as a consolidated, uniform, and complete system, although in some isolated and exceptional manuscripts there are remnants of other systems.
There are seven vowels, for which there are eight signs, and it is clear that they do not indicate quantity in any way. This system, like its predecessors, was used by different communities and by people who had different traditions of pronunciation and who interpreted the signs and read them accordingly.
Despite the fact that actual evidence for the conditions necessary for the writing down of the Masorah is rather late, there is clear evidence from other sources that the Masorah was committed to writing prior to the eighth century. (…). The proofs point to a period of 200 years within which vocalization and accentuation signs were initiated: not before the sixth century nor later than the seventh. This terminus a quo is based on a number of facts:
(1) Jerome (end of the fourth century-beginning of the fifth) states explicitly (in his commentary on the Bible) that the Jews did not have signs to note the vowels (he does not speak of accents).
(2) In the Jerusalem Talmud (which was completed in the first half of the fifth century) and in the Babylonian Talmud (which was completed at the end of the fifth century) there is no mention of vowel and accentuation signs; similarly there is no mention of them in the earliest Midrashim. Evidence from late Midrashim is obviously not reliable; for example in Exodus Rabbah, ch. 2:6 (to Ex. 3:4) csp(paseq) is actually mentioned, but this Midrash is later than the tenth century. It follows, therefore, that the use of the vowel and accentuation signs was not instituted before the sixth century. The terminus ad quem (the limit to which; destination) is established by a number of indirect proofs:
(1) Phinehas Rosh ha-Yeshivah is one of the early masoretes about whose work in Masorah and vocalization there is definite knowledge, and he lived in the first half of the ninth century at the latest. This suggests that vocalization and accentuation signs were already in use before then.
(2) Asher b. Nehemiah (the grandfather of Aaron Ben-Asher) lived apparently at the same time as Phinehas, and his grandfather Asher was the "great elder," the founder of the dynasty of famous masoretes who dealt with vocalization and accentuation signs like his descendants. This Asher the Elder must have lived in the second half of the eighth century at the latest, which means that the vowel and accentuation signs were fixed before that time.
(3) In the ninth century there was already no definite knowledge as to who invented the vowel and accentuation signs, and so we hear from Natronai Gaon of Babylonia (d, 858) in his prayer book, Me'ah Berakhot: "The vowel signs (niqqud) were not given at Sinai but the sages marked them by signs." Thus in the first half of the ninth century, although vowel and accent signs were known and accepted, the inventors were unknown. It can be assumed therefore that the institution of their use preceded that time by several centuries [This is mere 'assumption' and not a proven fact.].
From the above statement it can only be asserted that no vocalization system existed for the Hebrew of the OT. It does not show on sound basis that any vocalization system was in practice before the eighth century.
To recapitulate the whole of the above article, its salient features are being reproduced below (the word 'reproduced' has been used here, because in most of the cases they have been copied 'verbatim'):
a) The words are formed by placing the consonants together but they cannot be pronounced until some proper vocalization/diacritical signs be applied.
b) The vocalization consists of little signs written below, within, or above the consonants to indicate correct pronunciation.
c) Some languages had to evolve their own systems of vowel signs. As far as Hebrew is concerned it was void of any such vowel signs until seventh century AD.
d) In its original state only the consonants were written, the vowel signs being left to be filled up by the reader's mind. (…). This ancient practice of omitting the vowels is one fertile cause of varieties in the text, for it will readily be understood that doubts might often occur as to the proper vowels to be supplied to a group of consonants.
e) The absence of vowels meant that many a Hebrew consonant group could be differently pronounced, and from this resulted the fact that a variety of meanings could be attached to one and the same word in the original. When ultimately vowels were introduced into the Hebrew text of the Bible, these pronunciation variants sometimes became the bases of variae lections (various readings)
f) Before about 1000 BC, the early Hebrew alphabet had begun its autonomous development.
It took early Hebrew alphabet almost one thousand years (i.e. about the start of the Common/Christian Era) to evolve into the modern square Hebrew alphabet.
h) As Hebrew speech passed out of daily use, and familiarity with Biblical Hebrew steadily declined, it became necessary to introduce some form of vocal distinction, so that the Torah could be read and explained correctly.
i) Not even the most perfect copyist could ensure an unambiguous text, for Hebrew was written entirely without vowels, which the reader had to supply for himself.
j) The Massoretes naturally vocalized the text according to the practice of their own day. From this Massoretic text, in 'pointed' Hebrew, we can know fairly well how Hebrew sounded when it was solemnly chanted in a synagogue as long ago as, say, the time of Mohammed. But we have no such clear knowledge of how it may have been pronounced by David or Solomon.
k) The Massoretes themselves frequently misled posterity by faulty vocalization that changed the meaning.
l) Vocalization and accentuation are post-Talmudic, because there is no mention of them in Talmud.
In the passage under discussion, Solomon, after giving fairly detailed attributes of his beloved from his uncle ancestor (Ishma'el)'s progeny, pronounces his actual proper name 'Muhammad', which, according to the unvocalized consonantal alphabet was inevitably to be written as 'M+H+M+D'. When there genuinely and physically exists an exact application of this word, it is misleading to translate this proper noun or to apply it to Jesus Christ.