Narrated 'Uqba bin Al-Harith:

I married a woman and later on a woman came and said, "I suckled you both." So, I went to the Prophet (to ask him about it). He said, "How can you (keep her as a wife) when it has been said (that you were foster brother and sister)? Leave (divorce) her.

حَدَّثَنَا أَبُو عَاصِمٍ، عَنْ عُمَرَ بْنِ سَعِيدٍ، عَنِ ابْنِ أَبِي مُلَيْكَةَ، عَنْ عُقْبَةَ بْنِ الْحَارِثِ، قَالَ تَزَوَّجْتُ امْرَأَةً فَجَاءَتِ امْرَأَةٌ فَقَالَتْ إِنِّي قَدْ أَرْضَعْتُكُمَا. فَأَتَيْتُ النَّبِيَّ ﷺ فَقَالَ " وَكَيْفَ وَقَدْ قِيلَ دَعْهَا عَنْكَ " أَوْ نَحْوَهُ.