Swearing to Divorce Three Times For the Purpose of Obliging Someone

Question :

What is your opinion regarding a man who swears an oath to one divorce three times to a Muslim brother, saying that verily, he will do such-and-such, and he does not do it? Is the oath implemented upon the wife? What is the ruling of Islam if that oath is not implemented? Benefit us (with advice) and may Allah benefit you (with reward)

Answer:

If a person swears three times to divorce if so-and-so does such-and-such, or does not do such-and-such, or he says three times: "I must divorce my wife if I don't make a wedding party for so-and-so," or "if I do not speak to so-and-so," then that requires clarification: If the intention was to compel (someone) and emphasize and not that divorce should actually take place, then the ruling on this is one of an oath. Then it requires an atonement for an unfulfilled oath, which is to feed ten poor persons or to clothe them, or to free a slave. If he is unable to do these things, then he must fast for three (consecutive) days.

But if his intention was that divorce should take place if he did not do this thing, then one divorce of his wife takes place, even if he pronounced it three times, according to the correct view. He may take her back, as long as she is still in her waiting period. But if she has completed her waiting period before he takes her back, she is not permissible to him except with a new marriage and all of its accepted conditions. This is because evidence has been authentically reported from the Prophet proving that pronouncing divorce three times at one time is considered as one divorce, according to what was reported by Muslim from the Hadith of Ibn 'Abbas, may Allah be pleased with them.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 6 Pages 386-387