Ruling on Giving a Gift to Some of One's Children Exclusively

Question:
The last letter in our hands, which we received from the Noble Makkah, is from the presenter (M. M. Abu Abdullah). He says in his letter: I have a son and a daughter who are full siblings, and I also have a son and a daughter who are half-siblings. I wish to buy a house for the daughter who has no full brother, because she has not married and her marriage has been delayed. Is that permissible?
May Allah guide you.

Answer:
It is not permissible for a Muslim to give something exclusively to some of his children, and likewise, a woman may not give something exclusively to some of her children. This is because the Messenger of Allah (peace and blessings be upon him) said: Therefore, a Muslim may not give something exclusively to some of his children, or give some of them more than others. Rather, he must be just. Even if the daughter has no full brother, Allah, who has legislated in inheritance and distributed it, is the guardian of all of them. So neither a man nor a woman may give something exclusively to some of their children, or give some of them more than others. Rather, that is blameworthy, and it is obligatory to be just with all of them, based on the aforementioned hadith: And Allah knows best.

The presenter: Now, for example, if it happened that he gave something exclusively to one of his sons, does this remain valid after his death, or is it returned to...?

The Shaykh: The correct view is that it does not remain valid. If he gave something exclusively to them, or gave some of them more than others, and then he died, they have the choice. If they wish, they may accept it and forgive him, and if they wish, they may return it. It is permissible for them to return it, according to the correct view. Some scholars said that it remains valid after death and nothing is returned. But the correct view is that it does not remain valid, because the Prophet (peace and blessings be upon him) called it injustice. He said: He called the excess and the lack of justice injustice, and injustice is not approved. So if he dies after this sin, after the exclusive giving or the preference, the money is taken from the one who gave it exclusively and distributed among the heirs. Likewise, the excess is taken from the one who preferred some and distributed among the heirs, unless they forgive him. They are accountable and guided. If the guided one forgives his right, there is no harm.

The presenter: Thank you, may Allah reward you.