The ruling on giving a gift to one son to the exclusion of another

Question: Is it permissible for me to give one of my sons something that I do not give to another, because the other is wealthy?

Answer: It is not permissible for you to single out one of your children, male or female, with something to the exclusion of the other. Rather, it is obligatory to be just among them according to the rules of inheritance, or to leave them all without giving any of them a gift. This is based on the saying of the Prophet (peace and blessings be upon him): It is agreed upon that it is authentic.
However, if they are content with one of them being singled out with something, there is no harm, provided that those who are content are adults and of sound mind. Likewise, if among your children there is one who is deficient and unable to earn a living due to an illness or a condition that prevents earning, and he has no father or brother to provide for him, and he has no salary from the state to meet his needs, then it is obligatory for you to provide for him to the extent of his need until Allah makes him independent of that.