is calculated on a basis of six shares: the husband receives one-half, three shares; the mother receives one-third, two shares; and one-sixth remains. The rule we have understood is that, if only one-sixth remains, the grandfather takes it and the siblings are excluded. Here, however, we say: the grandfather receives one-sixth, while the sister receives one-half, three shares. Thus, she is allotted a fixed share alongside the grandfather, and the denominator is increased to nine. Thereafter, the grandfather reclaims from the sister, saying: “You took three shares and I took one, yet I am like a brother.” So their combined shares—four—are divided between them, with the male receiving the share of two females. Thus, this woman first inherited by fixed share and then, secondly, as a residuary heir.

Divide four by three, because the grandfather represents two units, and the number does not divide evenly and is relatively prime [to three], since any two consecutive numbers are relatively prime. This is a rule concerning the base numbers of inheritance cases. When it is relatively prime, multiply their number of units, three, by nine, the original denominator of the case, making twenty-seven, from which the division is correctly made. The husband receives three times three, or nine; the mother receives two times three, or six; and the remaining twelve go to the grandfather, who receives eight, and the sister, who receives four. This is why it is posed as a riddle: a case in which the first heir inherits one-third, the second one-third of what remains, the third one-third of what remains, and the fourth—the grandfather—what remains.

It was called al-Akdariyyah. It is said that a man named Akdar asked about it; and it is said that the husband in this case was named Akdar; and it is said that it confused the inheritance principles of Zayd ibn Thabit, because one of his principles was that, if only one-sixth remained, the grandfather took it and the siblings were excluded. Another of his principles was that the denominator is not increased in cases involving the grandfather except in this one. Thus, it confused his principles and was named al-Akdariyyah.

Why was it not called al-Mukaddirah (the confusing case)? Because Akdar is an elative form, and its confusion of the principles is severe; therefore it was called al-Akdariyyah. In fact, it confused the principles of Zayd ibn