Hadith 10:576
Abu Bakr narrated to us, he said: Abd al-Rahman ibn Muhammad al-Muharibi narrated to us, from Layth, from Ata, Tawus, and Mujahid, regarding a Christian man who has a Christian woman under him (as his wife), and she accepts Islam. They said: If he accepts Islam with her, then she is his wife. And if he does not accept Islam, they are separated.
حدثنا أبو بكر قال نا عبد الرحمن بن محمد المحاربي عن ليث عن عطاء وطاوس ومجاهد في نصراني تكون تحته نصرانية فتسلم قالوا إن أسلم معها فهي امراته وإن لم يسلم فرق بينهما