Is there a way to annul the divorce vow (yamin al-talaq) uttered by the husband to his wife: "You are divorced if you visit so-and-so," especially since he clarified to her that he intended it as a divorce of separation and not a divorce of threat, while his original intention was to threaten and prevent?

There is no difference, according to the majority of scholars, between intending a threat and intending a divorce in a conditional divorce. However, Ibn Taymiyyah and those who agreed with him differentiated between the two. If the wife visits the woman who was the subject of the condition, a divorce occurs according to the majority. Whereas Ibn Taymiyyah holds that the speaker must offer an expiation for an oath (kaffarat yamin) if he intended a threat, and if he intended a divorce, then he is bound by it unless he retracts his condition. The expiation for an oath is feeding ten needy persons, or clothing them, or emancipating a slave; and if one is unable, then fasting for three days. In the event of a divorce, the wife can be taken back before the expiry of her 'iddah (waiting period), provided that this divorce does not complete the three divorces.