The issue of sexual intimacy between a husband and wife has given rise to a lot of confusion. It needs to be appreciated that in this regard as per the Qur'ān and its dictates, three things stand prohibited:
1. Intercourse during menses.
2. Anal intercourse.
3. Oral Intercourse.
These restrictions are mentioned in the following verse of the Qur'ān:
وَيَسْأَلُونَكَ عَنِ الْمَحِيضِ قُلْ هُوَ أَذًى فَاعْتَزِلُواْ النِّسَاء فِي الْمَحِيضِ وَلاَ تَقْرَبُوهُنَّ حَتَّىَ يَطْهُرْنَ فَإِذَا تَطَهَّرْنَ فَأْتُوهُنَّ مِنْ حَيْثُ أَمَرَكُمُ اللّهُ إِنَّ اللّهَ يُحِبُّ التَّوَّابِينَ وَيُحِبُّ الْمُتَطَهِّرِينَ (2: 222)
They ask you concerning women's courses. Tell them: "They are an impurity. So keep away from women in their courses and do not approach them until they have cleansed themselves from blood. But when they have purified themselves after taking a bath, approach them in the manner the Almighty has directed you [in your instincts]. Indeed, Allah loves those who constantly repent and keep themselves clean." (2:222)
This means that, barring these three restrictions, everything else has been left to the taste and inclination of the husband and wife. The freedom they have in this regard is very aptly expressed in the following verse:
نِسَآؤُكُمْ حَرْثٌ لَّكُمْ فَأْتُواْ حَرْثَكُمْ أَنَّى شِئْتُمْ وَقَدِّمُواْ لأَنفُسِكُمْ وَاتَّقُواْ اللّهَ وَاعْلَمُواْ أَنَّكُم مُّلاَقُوهُ وَبَشِّرِ الْمُؤْمِنِينَ(2: 223)
These women of yours are your cultivated land; go, then, into your lands in any manner you please [and through this] plan for the future[of both this and the next world] and remain fearful to God. And bear in mind that you shall necessarily meet Him [one day]. And [O Prophet!] Give good tidings [of success and salvation] to the believers [on that Day]. (2:223)
The portion of the verse: "So come to your cultivated land in whatever manner you want to" refers to the liberty and freedom with which a person is allowed to come close to his wife. It is similar to how a farmer approaches his land. While explaining the expression
أَنَّى شِئْتُمْ فَأْتُوا حَرْثَكُمْ(go then, into your cultivatedlands in any manner you please), Amīn Ahsan Islāhī writes:
[This] alludes simultaneously to two things: On the one hand, it refers to the liberty, freedom and free manner with which a farmer approaches his land, and on the other hand refers to the responsibility, caution and care which he must exercise in approaching his land. The word حَرْثٌrefers to the latter and the word أَنَّى شِئْتُمْto the former. It is both this liberty and caution which ascertain the correct behaviour of a husband with his wife in this regard.
Everyone knows that the real bliss of married life is the freedom a person has in intimate affairs barring a few broad restrictions. The feeling of this freedom has a great amount of euphoria around it. When a person is with his wife in intimate moments, Divine will seems to be that he be overcome with emotion but at the same time it is pointed out to him that he has come into a field and an orchard; it is no wasteland or a forest. He may come to it in whatever manner and in whatever way whenever he pleases, but he must not forget that he has landed in his orchard. The Qur'ān has no objection on the discretion, choice and majesty with which he approaches his field if he knows full well where he is going and in no way is oblivious of this reality.
One aspect of the husband and wife relationship is that while fulfilling many other needs, it is also a means of satisfying the sexual urge. If this urge is satisfied between them, it secures their modesty and curbs sexual anarchy. However, if this urge is not quenched between the two, it might lead to grave deviations. It is because this relationship shields a husband and wife from any deviations that they are called each other's robes:
هُنَّ لِبَاسٌ لَّكُمْ وَ أَنْتُمْ لِبَاسٌ لَهُنَّ (2 :187)
They [your wives] are [like] a robe for you and you [like] a robe for them. (2:187)
One can construe in the light of what has been said above that Islam has neither imposed any restriction on the position or posture for sexual intimacy. However, a person must always bear in mind that Islam is a religion that stands for purification and cleanliness – both physical and spiritual. A person's own nature, if it is not perverted, guides him to be selective and refined in exercising this discretion. He may have the liberty to do anything in this regard, but he should always remember that the spirit and essence of this liberty dictate that he should not become an animal.
It also needs to be appreciated that during menses, only sexual intercourse is forbidden as is evident from 2:222 quoted above. Other forms of sexual intimacy are allowed. Anas ibn Mālik (rta) reports:
أَنَّ الْيَهُودَ كَانُوا إذا حَاضَتْ الْمَرْأَةُ فِيهِمْ لم يُؤَاكِلُوهَا ولم يُجَامِعُوهُنَّ في الْبُيُوتِ فَسَأَلَ أَصْحَابُ النبي صلى الله عليه وسلم النبي صلى الله عليه وسلم فَأَنْزَلَ الله تَعَالَى وَيَسْأَلُونَكَ عن الْمَحِيضِ قُلْ هو أَذًى فَاعْتَزِلُوا النِّسَاءَ في الْمَحِيضِ إلى آخِرِ الْآيَةِ فقال رسول اللَّهِ صلى الله عليه وسلم اصْنَعُوا كُلَّ شَيْءٍ إلا النِّكَاحَ
Amongst the Jews, when a woman menstruated, they did not dine with her nor did they live with her in their houses. So the companions of the Prophet asked him and Allah revealed ... (See 2:222 above). The Prophet then said: "You can do everything except having intercourse with her."