When the full sisters have already received the maximum allotment of two-thirds, the paternal sisters are left with no share—exactly like granddaughters through a son when full daughters are present. If there is only a single full sister, however, the paternal sisters take whatever is needed to complete the two-thirds, namely one-sixth.
The jurists then disagreed about the case in which a male paternal sibling accompanies the paternal sisters. The majority hold that he renders them agnate heirs: they divide the remainder of the estate, the male receiving the share of two females, just as with granddaughters through a son when grandsons are present alongside full daughters. Mālik stipulates that the male be of the same generational tier as the sisters.
Ibn Masʿūd said that once the full sisters have filled out the two-thirds, the residue belongs to the paternal brothers alone, not to the paternal sisters; Abū Thawr concurred. Dāwūd dissented on this point—though he agrees with them in the analogous situation involving full daughters and grandsons—arguing that if the two-thirds have not been completed, the paternal siblings inherit with the male taking twice the share of the female, unless this would give the women more than one-sixth, as happens when a full daughter coexists with grandsons.
The evidences marshalled by both sides in this dispute are, in fact, the very same proofs already discussed.
All scholars nonetheless agree that paternal siblings replace full siblings when the latter are absent, exactly as grandsons succeed sons; and that when a male is present among them he agnates the females: after the fixed shares are distributed, they divide the remainder, the male receiving twice the share of the female, just like sons—save for one exceptional situation, the problem known as “the Shared Case” (al-mushārakah).
This case concerns a woman who dies leaving her husband, her mother, her maternal siblings, and her full siblings. ʿUmar, ʿUthmān, and Zayd ibn Thābit would allot one-half to the husband, one-sixth to the mother, and one-third to the maternal siblings, thereby exhausting the estate and leaving the full siblings without a share. To remedy this they included the full siblings in that one-third together with the maternal siblings, distributing it among them so that the male takes the portion of two females. Among the jurists who adopt this principle of inclusion are Mālik, al-Shāfiʿī, and al-Thawrī.
ʿAlī (may Allah be pleased with him), Ubayy ibn Kaʿb, and Abū Mūsā al-Ashʿarī, on the other hand, did not admit the full siblings to that third alongside the maternal siblings and awarded them nothing. Their view is shared by Abū Ḥanīfah, Ibn Abī Laylā, Aḥmad, Abū Thawr, Dāwūd, and others.
The first group argues that full siblings share with maternal siblings the very cause that entitles them to inherit—the mother—and therefore cannot be excluded, for whenever heirs share the same cause they must share the estate. The second group counters that full siblings are agnate heirs, and agnates take nothing when the fixed shares of the quota holders fully consume the inheritance.
Their principal evidence is the consensus that if a deceased person leaves a spouse, a mother, one maternal brother, and ten or more full siblings, the maternal brother is entitled to a complete one-sixth, and the remaining one-sixth is divided among the others even though they