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.  

أَنَّ امْرَأَةً جَاءَتْ إِلَى النَّبِيِّ ﷺ فَأَسْلَمَتْ فَتَزَوَّجَهَا رَجُلٌ قَالَ فَجَاءَ زَوْجُهَا الأَوَّلُ فَقَالَ يَا رَسُولَ اللَّهِ إِنِّي قَدْ كُنْتُ أَسْلَمْتُ مَعَهَا وَعَلِمَتْ بِإِسْلاَمِي قَالَ فَانْتَزَعَهَا رَسُولُ اللَّهِ ﷺ مِنْ زَوْجِهَا الآخَرِ وَرَدَّهَا إِلَى زَوْجِهَا الأَوَّلِ  

the Messenger of Allah returned his daughter to Abul-'As bin Rabi' after two years, on the basis of the first marriage contract.  

أَنَّ رَسُولَ اللَّهِ ﷺ رَدَّ ابْنَتَهُ عَلَى أَبِي الْعَاصِ بْنِ الرَّبِيعِ بَعْدَ سَنَتَيْنِ بِنِكَاحِهَا الأَوَّلِ  

the Messenger of Allah, returned his daughter Zainab to Abul-As bin Rabi', with a new marriage contract.  

أَنَّ رَسُولَ اللَّهِ ﷺ رَدَّ ابْنَتَهُ زَيْنَبَ عَلَى أَبِي الْعَاصِ بْنِ الرَّبِيعِ بِنِكَاحٍ جَدِيدٍ