It was narrated from Ibn 'Abbas that:
a woman came to the Prophet and became Muslim, and a man married her. Then her first husband came and said: "O Messenger of Allah, I became Muslim with her, and she knew that I was Muslim." So the Messenger of Allah took her away from her second husband and returned her to her first husband. (JA)
English reference (JA): Vol. 3, Book 9, Hadith 2008 (JA)
Arabic reference (JA): Book 9, Hadith 2086 (JA)