Condition 3: the absence of any inheriting male ascendant—that is, the father and, on the sounder opinion, the paternal grandfather.

Condition 4: the absence of any inheriting descendant: the son, the son’s son no matter how remote, the daughter, and the son’s daughter no matter how remote.

The evidence for these two conditions is that brothers and sisters inherit only in a case of kalālah, and kalālah is one who leaves neither parent nor child.

A paternal sister receives one-half when five conditions are met: the four conditions just mentioned for the full sister, plus a fifth—the absence of a full brother or full sister, for whichever of them is present outranks her.

Two or more full sisters together receive two-thirds of the estate, as the Most High says, “But if there are two sisters, they shall share two-thirds of what he left.” They are entitled to that two-thirds only when four conditions obtain:

1. That they number two or more, in keeping with the divine words, “But if there are two sisters…”.
2. The absence of an agnatic counterpart who would make them residuaries, namely one or more full brothers, as in His statement, “If there are brothers and sisters together, the male shall receive the share of two females.”
3. The absence of any inheriting descendant—children or children’s sons—because Allah says, “If a person dies leaving no child and leaves a sister, she shall have one-half of what he left…”.
4. The absence of any inheriting male ascendant, namely the father by consensus, and the paternal grandfather according to the sounder view.