What is the ruling on the father claiming ownership of the property he bought and registered in the mother's name, despite his initial intention for it to be hers, and conditioning the waiver of the property on the mother's request for divorce?

If a man gifts a house to his wife with the intention of pleasing her and reassuring her, he cannot later claim that he did so to evade taxes. The fundamental principle is that it is forbidden for the giver to retract his gift, based on the Prophet Muhammad's (peace be upon him) saying: "It is not lawful for a man to give a gift or a donation and then retract it, except for a father in what he gives to his child. And the example of one who gives a gift and then retracts it is like that of a dog that eats until it is full, then vomits, and then returns to its vomit."

However, if the purpose of the gift was to gain the wife's affection or strengthen their bond, and the wife desires separation, then he may retract it. It is reported in Malik's Muwatta from Umar ibn Al-Khattab: "Whoever gives a gift for the sake of kinship or as an act of charity: he shall not retract it. But whoever gives a gift intending to be rewarded for it, he has the right to retract it if he is not satisfied with it." And anything that is given as a gift or a present for a specific reason, its validity lasts as long as that reason exists and ceases when it ceases.