Is it permissible for a father to give his son extra money without knowing the reason for the request, given the father's agreement to any amount the son asks for?

It is permissible for a father to give money to his son without knowing how it will be spent, provided two conditions are met:

1. The son must be an adult and of sound judgment. It is not permissible to give money to a minor or an imprudent person, for Allah Almighty says: "And do not give the imprudent your wealth which Allah has made a means of sustenance for you." However, a minor is permitted to dispose of a small amount. 2. The father must not know, or have a strong suspicion, that the son will spend the money on something forbidden. Otherwise, it is not permissible to give it to him, for Allah Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression."

It is not permissible for a son to take money from his father without his knowledge.