What is the ruling on a man selling his house to his daughter with a written contract for a specific sum, when there is a suspicion that the sale was only to disinherit his son, especially since the sale was concealed until after his death?

A father has the right to sell or gift his house to his daughter. If he sells it to her as a real sale, with immediate transfer of ownership, then she must pay the price. If she does not pay it until the father dies, then she must pay it to the heirs, and she will also receive her share of the inheritance. If he gifts the house to her while he is healthy, in the form of a sale, then this is a binding gift if she takes possession of it during his lifetime and disposes of it. However, if possession does not occur before his death, the gift is invalid according to the majority of scholars. The inquirer's doubt regarding the deceased's intention to disinherit him has no bearing on a real sale. As for a gift made with the intention of disinheriting the inquirer, there is a difference of opinion among scholars regarding its validity. Some consider it valid and enforceable, while others consider it unenforceable. The matter may require recourse to the judiciary.