Maliks Muwatta Book 29, Hadith Number 10.

Section : What is Clear about Giving Wives Right of Divorce.

Yahya related to me from Malik that he had heard that a man came to Abdullah ibn Umar, and said, “Abu Abd ar-Rahman! I placed the command of my wife in her hand, and she divorced herself, what do you think?” Abdullah ibn Umar said, “I think that it is as she said.” The man said, “Don’t do it, Abu Abd ar-Rahman!” Ibn Umar said, “You did it, it has nothing to do with me.”