Sahih Muslim Book 9, Hadith Number 3494.

Chapter: Atonement is essential for one who made his wife unlawful for himself without the intention of divorce.

Ibn Abbas (Allah be pleased with them) reported about (declaring of one’s woman) unlawful as an oath which must be atoned, and Ibn ‘Abbas said: Verily, there is in the Messenger of Allah (may peace be upon him) a model pattern for you.