and as for his parents...
and as for his parents, each of them shall have a sixth part of the inheritance if he has a child, ..." The second state: is when there exists no child and the inheritors are only the parents. In this case one thirds of the whole wealth belongs to the mother and the rest of it belongs to the father, as the verse says: "...
but if he has no child and his parents be his heirs, then his mother shall have the third, ..." The third state: is when the inheritors are only parents and he has no offspring but he has brother(s) from the side of his parents or only from the side of his father. Then, the portion of the mother decreases from one third to one-sixth and the remaining five-sixth of the inheritance belongs to the father. It says: "...
and if he has brothers, then his mother shall have the sixth, ..." In fact, brothers, who do not inherit anything, prevent the additional amount of the inheritance of the mother, and that is why, in Arabic language, they are called: /h¤ajib/ 'chamberlain'. Then, the Qur'an says that all of these things are after fulfilling the bequest that the diseased has bequeathed, and paying his debts, saying thus: "... after (the payment of) a bequest he may have bequeathed or a debt.
..." It should be noticed, of course, that only one third of the property can be bequeathed on. Therefore, if a person bequeaths more than that, it is not valid unless the heirs permit. In the next sentence, it says: "... You do not know which of your parents and your children is closer to you in usefulness. ..." Then, at the end of the verse, it remarks that: "... (This is) an ordinance from Allah.
Verily Allah is All-Knowing, All-Wise." This statement is considered as an emphasis upon the former subjects so that there remains no place for people to bargain about the laws of the portions of heritance. Why Is the Heritance of Man Equal of the Portion of Two Women? With reference to the Islamic literature we realize that this question has actively existed in the minds of people since the beginning of Islam. They sometimes asked questions from the leaders of Islam on this regard.
For example, it is narrated that Imam Ali-ibn-Musa-r-Rida, in answer to this question, said: " The fact that the portion of women from inheritance is equal to the half of the portion of men is for the reason that when a lady marries she takes something (dower) and man should give something.