Does the inheritance revert to the deceased's father or to his children if he dies while his father is still alive?

If a person dies and is survived by a father and male children, or male and female children, the father receives one-sixth, and the wife receives one-eighth (if she exists). The remainder goes to the children, with the male receiving the share of two females.

However, if the children are only females (one daughter or more), the wife receives one-eighth (if she exists), and the daughter or daughters receive their share (half for one, and two-thirds for two or more daughters). Then, the father receives one-sixth in addition to what remains of the inheritance after the shares of the wife and daughters.

The proof for this is Allah's saying: "Allah instructs you concerning your children: for the male, what is equal to the share of two females. But if there are [only] daughters, two or more, for them is two thirds of what he left. And if there is only one, she will have half. And for his parents, for each of them is one sixth of what he left if he had a child" (An-Nisa: 11).

The father has three situations in inheritance: 1. By fixed share only: With a son or a grandson, he receives only one-sixth. 2. By residuary share only: In the absence of children (males or females), he takes all the wealth if he is alone, or what remains after the fixed share recipients (like the wife and mother). 3. By combining fixed share and residuary share: With female children (a daughter or a granddaughter), he receives one-sixth as a fixed share, then he takes the remainder as a residuary share, based on the saying of the Prophet (peace be upon him): "Give the prescribed shares to their deserving recipients, and whatever remains is for the nearest male relative." This is by agreement of the scholars.