Is it permissible for a father to financially assist one of his children in purchasing and building a house while concealing the matter from some of his other children for fear that they will demand the same, and should the father be informed of the Sharia ruling? And is the father obliged to give the rest of the children—males and females—the same amount, or assist them in other matters such as building a house for them?

A father's favoring of some of his children over others in a gift, without justification, is an injustice that incites discord and animosity. It is obligatory for the father to equalize them in giving, unless there is a legitimate reason, such as illness or urgent need. If this justification does not exist, then favoring one over another is forbidden.

Equality among children is achieved by giving the male the same amount as the female in a gift, not like in inheritance.

It is obligatory for the father who favored one of his children to return the excess during his lifetime. If he dies without returning it, it must be returned after his death.

The questioner must explain the religious ruling to his father in a wise and appropriate manner, preserving the father's standing, clearing his conscience, and achieving the best interest of both the father and the children.