It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them): A woman got married during the time of the Messenger of Allah (peace and blessings be upon him), and she had accepted Islam. Then her (first) husband came and said: I had accepted Islam along with her. So the Messenger of Allah (peace and blessings be upon him) separated her from her later husband and returned her to her first husband.
Hadith Referenceمسند اسحاق بن راهويه / كتاب النكاح و الطلاق / 654
Hadith Takhrij«سنن ابوداود ، كتاب الطلاق ، باب اذا اسلم احد الزوجين ، رقم : 2239 . سنن ترمذي ، ابواب النكا ح ، باب ماجاء فى الزوجين المشركين الخ ، رقم : 1144 قال الشيخ الالباني : ضعيف .»