It is narrated from Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) that he was present on the occasion of the husband and wife who performed li'an (mutual imprecation) in the time of the Messenger of Allah (peace and blessings be upon him); they were separated, and the husband said: "O Messenger of Allah! If I keep her, I will have lied against her."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5670