What is the ruling of Islamic law regarding a man who conditioned his wife's divorce upon a condition, then regretted it and wants her to leave; will his wife be divorced if she leaves, considering his regret?

If a husband suspends his wife's divorce upon a specific action, and his wife performs that action exactly as the husband intended, the divorce takes effect according to the majority of scholars, including the four madhhabs. This is the preponderant opinion. However, if he did not intend divorce but rather intended prohibition or threat, then he must offer expiation for an oath (kaffarat yamin), according to Shaykh al-Islam Ibn Taymiyyah.

In the event that a divorce occurs, he may reconcile with her before her waiting period (iddah) ends, unless this divorce completes the three divorces. The husband's regret does not alter the Shar'i ruling according to the majority of scholars. However, Shaykh al-Islam Ibn Taymiyyah holds that if he intended divorce, he may retract it and the divorce does not take effect.