"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." (Using translation from Nasāʾī 3285)  

أَنَّ أُمَّ حَبِيبَةَ زَوْجَ النَّبِيِّ ﷺ قَالَتْ يَا رَسُولَ اللهِ أَنْكِحْ ابْنَةَ أَبِي تَعْنِي أُخْتَهَا فَقَالَ رَسُولُ اللهِ ﷺ «وَتُحِبِّينَ ذَاكَ؟» قَالَتْ نَعَمْ لَسْتُ لَكَ بِمُخْلِيَةٍ وَأَحَبُّ مَنْ شَارَكَنِي فِي خَيْرٍ أُخْتِي قَالَ رَسُولُ اللهِ ﷺ «فَإِنَّ ذَلِكَ لَا يَحِلُّ» قَالَتْ أُمُّ حَبِيبَةَ يَا رَسُولَ اللهِ وَاللهِ لَقَدْ تَحَدَّثْنَا أَنَّكَ تَنْكِحُ دُرَّةَ بِنْتَ أَبِي سَلَمَةَ فَقَالَ «بِنْتُ أُمِّ سَلَمَةَ؟» قَالَتْ أُمُّ حَبِيبَةَ نَعَمْ قَالَ رَسُولُ اللهِ ﷺ «فَوَاللهِ لَوْ أَنَّهَا لَمْ تَكُنْ رَبِيبَتِي فِي حَجْرِي مَا حَلَّتْ لِي إِنَّهَا لَابْنَةُ أَخِي مِنَ الرَّضَاعَةِ فَلَا تَعْرِضْنَ عَلَيَّ بَنَاتِكُنَّ وَلَا أَخَوَاتِكُنَّ»  

Um Habiba said to Messenger of Allah ﷺ "We have heard that you want to marry Durra bint Abu-Salama." Messenger of Allah ﷺ said, "Can she be married along with Um Salama (her mother)? Even if I have not married Um Salama, she would not be lawful for me to marry, for her father is my foster brother." (Using translation from Bukhārī 5123)  

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