What is the ruling on a father's bequest to purchase a house with his money after his death for his wife and unmarried daughter, given the need of one of the sons for his share of the inheritance? And what is the share of each heir from the aforementioned amount?

If a man dies leaving behind a wife, two sons, and two daughters, and no other heirs, then his wife receives one-eighth as a prescribed share due to the existence of inheriting descendants. The remainder goes to the two sons and two daughters by ta'sib (agnatic inheritance), with the male receiving the share of two females. The inheritance is divided into 48 shares: the wife receives 6 shares, each son receives 14 shares, and each daughter receives 7 shares.

As for the bequest to buy a house for the sister and mother, this is a bequest to an heir, which is forbidden by Islamic law and is not enforceable unless the rest of the heirs consent. It is not a binding bequest. Its enforceability depends on the consent of the mature and discerning heir. Any heir who does not consent has the right to take their full share. It is permissible to demand your share of the inheritance, while gently and wisely explaining the invalidity of the bequest to the mother.