"O Messenger of Allah, marry the daughter of my father" - meaning her sister. The Messenger of Allah said: "Would you like that?" She said: "Yes; I do not have you all to myself, and I would like to share this goodness with my sister." The Prophet said: "That is not permissible for me." Umm Habibah said: "O Messenger of Allah, by Allah, we have been saying that you want to marry Durrah bint Abi Salamah." He said: "The daughter of Umm Salamah?" I said: "Yes." He said: "By Allah, even if she were not my stepdaughter who is in my care, she would not be permissible for me (to marry), because she is the daughter of my brother through breast-feeding. Thuwaibah breastfed Abu Salamah and I. So do not offer your daughters or sisters to me in marriage."  

أَنَّ أُمَّ حَبِيبَةَ زَوْجَ النَّبِيِّ ﷺ قَالَتْ يَا رَسُولَ اللَّهِ أَنْكِحْ بِنْتَ أَبِي تَعْنِي أُخْتَهَا فَقَالَ رَسُولُ اللَّهِ ﷺ وَتُحِبِّينَ ذَلِكِ قَالَتْ نَعَمْ لَسْتُ لَكَ بِمُخْلِيَةٍ وَأَحَبُّ مَنْ شَرِكَتْنِي فِي خَيْرٍ أُخْتِي فَقَالَ رَسُولُ اللَّهِ ﷺ إِنَّ ذَلِكَ لاَ يَحِلُّ قَالَتْ أُمُّ حَبِيبَةَ يَا رَسُولَ اللَّهِ وَاللَّهِ لَقَدْ تَحَدَّثْنَا أَنَّكَ تَنْكِحُ دُرَّةَ بِنْتَ أَبِي سَلَمَةَ فَقَالَ بِنْتُ أُمِّ سَلَمَةَ قَالَتْ أُمُّ حَبِيبَةَ نَعَمْ قَالَ رَسُولُ اللَّهِ ﷺ فَوَاللَّهِ لَوْ أَنَّهَا لَمْ تَكُنْ رَبِيبَتِي فِي حَجْرِي مَا حَلَّتْ إِنَّهَا لاَبْنَةُ أَخِي مِنَ الرَّضَاعَةِ أَرْضَعَتْنِي وَأَبَا سَلَمَةَ ثُوَيْبَةُ فَلاَ تَعْرِضْنَ عَلَىَّ بَنَاتِكُنَّ وَلاَ أَخَوَاتِكُنَّ  

"We have been saying that you want to marry Durrah bint Abi Salamah." The Messenger of Allah said: "As a co-wife to Umm Salamah? Even if I were not married to Umm Salamah, she would not be permissible to me, for her father is my brother through breast-feeding."  

لِرَسُولِ اللَّهِ ﷺ إِنَّا قَدْ تَحَدَّثْنَا أَنَّكَ نَاكِحٌ دُرَّةَ بِنْتَ أَبِي سَلَمَةَ فَقَالَ رَسُولُ اللَّهِ ﷺ أَعَلَى أُمِّ سَلَمَةَ لَوْ أَنِّي لَمْ أَنْكِحْ أُمَّ سَلَمَةَ مَا حَلَّتْ لِي إِنَّ أَبَاهَا أَخِي مِنَ الرَّضَاعَةِ