Narrated Ibn `Abbas: The custom (in old days) was that the property of the deceased would be inherited by his offspring; as for the parents (of the deceased), they would inherit by the will of the deceased. Then Allah cancelled from that custom whatever He wished and fixed for the male double the amount inherited by the female, and for each parent a sixth (of the whole legacy) and for the wife an eighth or a fourth and for the husband a half or a fourth.

Narrated Ibn `Abbas: (In the Pre-Islamic Period) the children used to inherit all the property but the parents used to inherit only through a will. So Allah cancelled that which He liked to cancel and put decreed that the share of a son was to be twice the share of a daughter, and for the parents one-sixth for each one of them, or one third, and for the wife one-eighth or one-fourth, and for the husband one-half, or one-fourth.

Narrated Ibn `Abbas: (During the early days of Islam), the inheritance used to be given to one's offspring and legacy used to be bequeathed to the parents, then Allah cancelled what He wished from that order and decreed that the male should be given the equivalent of the portion of two females, and for the parents one-sixth for each of them, and for one's wife one-eighth (if the deceased has children) and one-fourth (if he has no children), for one's husband one-half (if the deceased has no children) and one-fourth (if she has children).