Guide me a single book in relation to history that is least unbiased and give a proper view of all the sects. Secondly, what is your opinion about books of Tabari and Ibn e Khuldun? My second question is that it is said very often that there are more than three hundred narratives in favor or praise of Hazrat Ali but I have studied Quran according to my capacity which does not show anything like until and unless you ponder upon the commentary which is often biased by the sectarian views and those verses can be fitted to anybody not only to Hazrat Ali. What would you suggest about this matter? Whose commentary is reliable?
The recording of history in Muslim scholarship unfortunately was not based on very scientific and systematic approach. Almost all of the books of history of Islam are collection of oral reports that have reached the author of the book with little attempt to verify their reliability. Many of the books of history in Islam do not even have accurate report of the chain of narrators of a historical event.
Accordingly it is not really easy to single out one book as the most trusted one. Every reported event in the books of history needs to be individually examined in terms of their reliability. This includes the books of Tabari and Ibn Khaldoun.
As for the verses of the Qur'an in praise of Ali (ra), a question that emerges is that why not even one of these verses refers to Ali (ra) in a way that we do not need to rely on commentaries and Ahadith to understand it? This of course does not mean that none of the referred verses are in praise of Ali (ra), and there is of course no doubt that a person like Ali (ra) deserves to have the best of praises.
The point however is that if the Qur'an wanted to give us a message about the person who was praised (rather than the act that was praised) then this message would have been explicit enough so that we could easily understand it. The fact is that the style of the Qur'an in general is to praise the deeds rather than persons, so that people get encouraged to do those deeds. When the Qur'an is adopting this style we too need to adopt the same style when benefitting from it.
Most of the commentaries that are available are based on Ahadith and therefore (like the case of history books) each of those Ahadith needs to be tested in terms of reliability.
For commentaries that are not based on Ahadith I suggest Tadabbur al-Qur'an by Maulana Islahi.