For Allah, the Exalted, only blocked her [the mother] by means of children and siblings, and there are neither children nor siblings here. Furthermore, Umar, Ali, and Ibn Mas'ud left the half for the sister and the sixth for the grandfather. As for Zayd, he combined her half with the sixth of the grandfather and divided it between them, because she does not deserve [anything] with him except by the rule of division (muqasama). Zayd only resorted to causing 'awl (increase of the denominator) in the issue here because if he did not assign a fixed share to the sister, she would fall out [of the inheritance], and there is no one in the obligatory share distribution who would cause her to fall out. It has been narrated from Qabisah ibn Dhu'ayb that he said: 'Zayd did not say that; rather, his companions drew an analogy based on his principles, but he himself did not clarify anything.' If it is said: 'The sister with the grandfather is a residuary (asabah), and the residuary falls out when the fixed shares are completed.' We say: 'The grandfather only makes her a residuary, and he is not a residuary with these [others]; rather, a fixed share is assigned to him. If there were a brother in place of the sister, he would have been excluded, because he is a residuary in his own right.' If there were another sister with the [first] sister, or a brother, or more than that, the mother would be reduced to the sixth, and the sixth would remain for them, which they would take, and the issue would not undergo 'awl. The base of the issue in the Akdariyyah is six, and it increased to nine. The shares of the sister and the grandfather are four between them, which, [when divided] by three, is not valid. So, you multiply three by nine, which becomes twenty-seven. Then, everyone who has anything from the base of the issue is multiplied by the three that you multiplied in the issue; so for the husband, three times three is nine, for the mother, two times three is six, and twelve remain between the grandfather and the sister divided by three; he has eight and she has four. It is used as a riddle, so it is said: Four people inherited the wealth of a deceased person, one of them took its third, the second took a third of what remained, the third took a third of what remained, and the fourth took what remained. It is also said: A woman came to some people and said, 'I am pregnant; if I give birth to a male, he has nothing; if I give birth to a female, she has a ninth of the wealth and a third of a ninth; and if I give birth to two children, they have the sixth.' It is also said: 'If I give birth to a male, I have a third of the wealth; if I give birth to a female, I have two-ninths; and if I give birth to two children, I have a sixth of it.'

Section: A wife, a mother, a sister, and a grandfather. For the wife is the fourth, for the mother is the third, and the remainder is between the grandfather and the sister divided by three; its base is twelve, and it is valid from thirty-six. If there were a brother in place of the sister, the remainder is between them as two halves, and it is valid from twenty-four. If there were two sisters, he divides with them, and it is valid from forty-eight. If there were a brother and a sister, or three sisters, they would reduce the mother to the sixth, divide the remainder among themselves by five, and it is valid from sixty. If they exceed that, the third of the remainder and the division (muqasama) are equal, so assign him a third of the remainder, multiply the issue by three, it becomes thirty-six, and twenty-one remains for him and them. He takes a third of it, which is seven, and the remainder is for them. If it is not valid for them, you multiply them or reconcile them with thirty-six, and whatever it reaches is what it is valid from. If they are from both sides [paternal and maternal], nothing remains for the son of the father [paternal half-sibling], and the child of both parents takes it all to the exclusion of them.