by Syed Mumtaz Ali & Rabia Mills
In the Islamic faith, the first and the foremost and the most reliable and highest form of religious law for faithful Muslims is contained within the holy Qur'an. The Prophetic Traditions (also known as Hadith, which are the sayings and doings and tacit approval of things said or done in the presence of the Prophet Muhammad, p.b.u.h.)(1) are a second source of law. With that said, we hope the following reply will answer your question.
According to Islam, procreation is not the sole and only purpose of marriage. While procreation is a primary purpose, companionship and enjoyment of the spouse along with avoidance of unlawful or sinful relationships are also secondary purposes. These secondary purposes play their own important roles in the Islamic teachings which govern sexual relations. In other words, although procreation is definitely an aim, it is not an exclusive aim. Procreation is the major purpose, but nonetheless enjoyment and other purposes also play significant roles in married life as evidenced by the Islamic teachings which relate to sexual relations.
Although the primary purpose of sex is procreation, the Qur'an does not forbid it when a woman reaches menopause. For example, in the Qur'an is the story is about the Prophet Zakariya a.s.(2) (Christian spelling -- Zakaria) [see Qur'an 19:1-15] who had fathered a child well into his old age. One verse in particular reads:
"He [Zakariya] said: "O my Lord! How shall I have a son, when my wife is barren and I have grown quite decrepit from old age?" [Qur'an 19:8]
"He said: "So (it will be): thy Lord saith, "That is easy for Me: I did indeed create thee before, when thou hadst been nothing!" [Qur'an 19:9]
The Qur'anic reference above, then, shows the case of a couple carrying on sexual relations well into old age. This in turn signifies that these relations are allowed within marriage and into old age for Muslim couples.