What is the religious ruling for someone who swore an oath of divorce to sell his house if he did not acquire half a meter of land from his brothers, then his father, who had willed that he should not acquire the land, passed away, and his brothers adhered to the will, knowing that selling the house would harm his brothers, and his wife rejects the idea of her divorce and return?

The wording and intention were not mentioned. The summary of the matter is that whoever swears by divorce, contingent on the occurrence or non-occurrence of an event: if he intended the divorce to take effect upon the occurrence of that event, his wife is divorced by the agreement of the jurists. However, if he intended another meaning, such as deterrence, then divorce occurs upon the fulfillment of the sworn-upon condition according to the majority of scholars. Others held that it does not occur, but rather he is obligated to offer an expiation for an oath (kaffarat yameen), and this is the choice of Ibn Taymiyyah and his student Ibn al-Qayyim.

We advise you to refrain from selling the house. If you sell it and break your oath, your wife is divorced with one pronouncement. Then you may take her back without needing a new contract or witnesses, and her knowledge is not a condition. If she asks you, tell her that you found a solution to your problem, without mentioning divorce and رجعة (taking her back) if it would lead to destabilizing the family.