What is the ruling of Islamic law regarding someone who swore an oath of triple divorce in a moment of intense anger that his mother would not enter his house, and he is now regretful and wishes to retract his oath and let his mother into his house?

The divorce of an angry person is valid unless he has lost his mind. The majority of scholars believe that a conditional divorce takes effect upon the fulfillment of the condition. However, Shaykh al-Islam Ibn Taymiyyah holds the view that it does not take effect if the intention was to deter or prevent, and in such a case, an expiation for breaking an oath is required. It is not possible to retract an oath of divorce according to the majority of scholars. If your mother enters, your wife becomes irrevocably divorced (talaq bainunah kubra). It is advised to be dutiful and kind to one's parents and to avoid swearing by divorce. The matter should be referred to the Sharia courts.