Does the expiation for an oath become obligatory upon the son if he violates his mother's oath, and what is the extent of this expiation?

Obeying one's parents is among the most emphasized obligations and best acts of devotion. Allah has conjoined His right to be thanked with their right, and the command to treat them with kindness with the prohibition of shirk. Therefore, do not disobey your mother's command if what she calls you to is good. If she is pleased and forgives you for your disobedience, then perhaps nothing will befall you. As for the oath, if abandoning what you swore to is better, then your action of abandoning it and expiating for the oath is correct, based on the Prophet, peace and blessings be upon him, who said: "Whoever takes an oath and then sees something better than it, let him do what is better and expiate for his oath."