What is the ruling of Sharia on the action of a father who sold land that the mother had bought with her own money and the father had registered in his name, and then did not give the unemployed son his share of the sale price?

If the land belonged to your mother, its ownership transfers to her heirs upon her death. Your father receives one-quarter, and the remainder goes to the other heirs.

It is permissible for a father to take from his son's wealth when in need, provided it does not harm the son, based on the Prophet Muhammad's (peace be upon him) saying: "You and your wealth belong to your father," and his saying: "You and your wealth belong to your father. Indeed, the purest of what you consume is from your earnings, and indeed, your children's wealth is from your earnings, so consume it with pleasure."

The majority of jurists stipulate for this permissibility: that the father be in need, that taking from the son does not harm him, and that he does not take to give to another sibling.

Therefore, if you are in need of your share and would be harmed by its taking, then it is not permissible for your father to take it.

You should seek someone whom your father trusts to speak with him, while observing filial piety and kindness towards him, for a father's injustice does not negate the duty of piety towards him.