And he [the grandfather] is excluded by the father, because he is related through him, so he is excluded by him, like brothers. Likewise, every grandfather is excluded by his son, because he is related through him. The grandfather is at a lower rank than the father in the case of a husband and two parents, and a wife and two parents, for the mother is assigned one-third of the entire estate in both cases, and the remainder goes to the grandfather, unlike the father.

1003 - Issue; he said: (The husband has the half if there is no child. If she has a child, he has the quarter. The woman has the quarter, whether she is one or four, if there is no child. If he has a child, they have the eighth).

In summary, the husband and wife are sharers (dhu fard); they do not inherit otherwise. The husband's share is the half when there is no child of the deceased wife or child of her son, and the quarter when there is a child or son's child. The share of the wife or wives is the quarter when there is no child of the husband or child of his son, and the eighth when there is a child or son's child; one or four are the same by the consensus of the scholars. The basis for this is the saying of Allah the Almighty: "And for you is half of what your wives leave if they have no child. But if they have a child, for you is one-fourth of what they leave, after any bequest they [may have] made or debt. And for the wives is one-fourth if you have no child. But if you have a child, then for them is one-eighth of what you leave, after any bequest you [may have] made or debt." He only assigned to the group the same as to the individual because if He had assigned the quarter to each individual, and they were four, they would have taken the entire estate, and their share would have exceeded the husband's share. The same is the case with grandmothers; the group is like the individual, because if each of the grandmothers took the one-sixth, they would have taken the half, thus exceeding the inheritance of the grandfather. As for the rest of the sharers, such as daughters, son's daughters, and all sisters who are separated, each group of them has the same as two, according to what was mentioned in its place, and they exceed the share of the individual, because the male who inherits at their degree has no fixed share, except for the siblings through the mother, for their male and female are equal, because they inherit by uterine kinship and pure maternal relationship.