– Alternatively, it may be said that Allah has attributed the inheritance to “the two parents” – the father and the mother – so the mother is entitled to one-third of what the two parents together inherit, while whatever the husband or wife receives is treated like the amount taken by a creditor. Allah knows best.
– As for the father, Allah has fixed for him one-sixth whenever the deceased leaves any children. If the children are male, the father receives no more than that one-sixth, and by consensus the sons have priority over him for the residuary share.
If the children are female, whether one or several, the father still receives one-sixth and the daughters take their prescribed portion; whatever remains goes to the nearest male heir, which here is the father, for he is closer than the brothers and their descendants or the paternal uncles and theirs. In this case the father therefore combines a fixed share with a residuary share.
Should the fixed shares exhaust the estate, the father receives nothing beyond his one-sixth, as in the case where the deceased leaves both parents and two daughters: each parent receives one-sixth and the two daughters two-thirds.
The clear implication of the noble verse is that when there are no children, male or female, the father inherits without a fixed proportion, as a residuary heir: he takes the entire estate if he is the sole heir, or whatever is left after the fixed shares when other Qur’anic heirs are present. This is the unanimous view.
The grandfather is treated like the father in all these rulings, except in the two cases known as the ʿUmariyyatayn (1), in which the mother inherits a full one-third alongside the grandfather.
As for the grandmother, her share is one-sixth when the mother is absent, a ruling established by the Sunnah.