According to Islam, a specific age for marriage hasn’t been mention and also a specific age difference between a man and a woman who want to marry each other also hasn’t been explained and there is no mention of whether the boy or girl should be younger or older at the time of marriage.
Although there is no specific age for marriage in Islam and no specific age difference is mentioned, the narrations narrated from the Holy Prophet Muhammad and the Infallible Imams and the practical life of those nobles are evidenced by his efforts to hasten marriage. According to the biography of the Infallibles and historical evidence, the marriage of the Imams took place at the age after puberty and before the age of twenty. The same was true of their grandchildren, who typically married before the age of twenty. In general, narrations are used that state that the basic age for marriage is after puberty, and if a person feels the need to do so in such a way that abandoning it causes sin, marriage becomes obligatory at this age.
On the other hand, the biography of the Infallibles and historical witnesses show that the Imams and the vicegerents of God, except for a few cases such as the marriage of Lady Khadijah with the Holy Prophet Muhammad, were older than their wives. Therefore, it may be said that in marriage, it is better for the man to be older than the woman but it is not yet possible to determine what the age difference was, as historical evidence suggests. At that time, this issue was not very important and the Imams had different age differences from their wives.
On the other hand, since there is usually a difference of two to six years between the maturity of girls and boys, it is better to observe this amount of difference in the marriage of girls and boys because scientific research and psychological and sociological findings have proved and confirmed this point. If the girl’s age is less than the boy’s age, he usually falls short of the man’s position and tries to be obedient. As this age difference increases, the woman’s sense of motherhood, sisterhood, or guardianship increases, for example, a woman who is 15 years or older than her husband always treats her husband like a mother or older sister. On the other hand, if the man is older, the woman can rely on him. At the same time, family management is not a problem, and women’s attractiveness to men is maintained and mutual understanding is enhanced.
Since the practice and tradition of the Infallibles is a model and proof for us, and the scientific findings that common sense has accepted have been confirmed by religion. In determining the age of marriage and whether the girl or boy is younger or older at the time of marriage, we can consider the life of those nobles and scientific findings as a religious criterion and norm and say that it is better in the marriage of girls and boys that the girl is a few years younger than the boy.