What is the ruling regarding the share of a grandmother when the deceased has no mother?
Chapter on the Roots of Inheritance Shares that Increase (Awl)
Al-Mughni
Book of Inheritance Shares (Farā'id)
Primary text
When the deceased has no mother, the grandmother receives one-sixth of the inheritance. There is a consensus among scholars on this ruling. Evidence is provided by the incident where a grandmother petitioned Abu Bakr for her inheritance, who initially found no textual basis for it in the Quran or Sunnah. However, Al-Mughirah ibn Shu'bah testified that the Prophet, peace be upon him, granted the grandmother one-sixth. Abu Bakr confirmed this upon testimony from Muhammad ibn Maslamah. Later, when another grandmother approached Umar, he upheld the previous ruling, stating that if both grandmothers are present, the one-sixth is divided equally between them, and if only one is present, she receives the entire one-sixth.
Supporting text
A dissenting narration exists from Ibn Abbas, claiming the grandmother stands in the place of the mother due to derivation, similar to how the grandfather replaces the father. However, it is established that the mother completely veils (blocks) grandmothers from inheriting from any direction, based on prophetic tradition, because the grandmother derives her right through the mother, thus falling when the mother is present, like a grandson falling due to the son.