(daughter of Abu Sufyan) I said, "O Messenger of Allah ﷺ! Marry my sister. the daughter of Abu Sufyan." The Prophet ﷺ said, "Do you like that?" I replied, "Yes, for even now I am not your only wife and I like that my sister should share the good with me." The Prophet ﷺ said, "But that is not lawful for me." I said, We have heard that you want to marry the daughter of Abu Salama." He said, "(You mean) the daughter of Um Salama?" I said, "Yes." He said, "Even if she were not my step-daughter, she would be unlawful for me to marry as she is my foster niece. I and Abu Salama were suckled by Thuwaiba. So you should not present to me your daughters or your sisters (in marriage)." Narrated 'Urwa: Thuwaiba was the freed slave girl of Abu Lahb whom he had manumitted, and then she suckled the Prophet. When Abu Lahb died, one of his relatives saw him in a dream in a very bad state and asked him, "What have you encountered?" Abu Lahb said, "I have not found any rest since I left you, except that I have been given water to drink in this (the space between his thumb and other fingers) and that is because of my manumitting Thuwaiba." (Using translation from Bukhārī 5101)   

أَنَّ زَيْنَبَ بِنْتَ أَبِي سَلَمَةَ وَأُمُّهَا أُمُّ سَلَمَةَ زَوْجُ النَّبِيِّ ﷺ أَخْبَرَتْهُ أَنَّ أُمَّ حَبِيبَةَ بِنْتَ أَبِي سُفْيَانَ أَخْبَرَتْهَا أَنَّهَا قَالَتْ يَا رَسُولَ اللهِ انْكِحْ أُخْتِي زَيْنَبَ بِنْتَ أَبِي سُفْيَانَ قَالَتْ فَقَالَ رَسُولُ اللهِ ﷺ أَوَ تُحِبِّينَ ذَلِكَ؟ قَالَتْ قُلْتُ نَعَمْ لَسْتُ لَكَ بِمُخْلِيَةٍ وَأَحَبُّ مَنْ شَارَكَنِي فِي خَيْرٍ أُخْتِي قَالَتْ فَقَالَ النَّبِيُّ ﷺ إِنَّ ذَلِكَ لَا يَحِلُّ لِي قَالَتْ فَقُلْتُ وَاللهِ يَا رَسُولَ اللهِ إِنَّا لَنَتَحَدَّثُ أَنَّكَ تُرِيدُ أَنْ تَنْكِحَ دُرَّةَ بِنْتَ أَبِي سَلَمَةَ قَالَ بِنْتَ أُمِّ سَلَمَةَ؟ قَالَتْ فَقُلْتُ نَعَمْ فَقَالَ وَاللهِ لَوْ أَنَّهَا لَمْ تَكُنْ رَبِيبَتِي فِي حِجْرِي مَا حَلَّتْ لِي إِنَّهَا لَابْنَةُ أَخِي مِنَ الرَّضَاعَةِ أَرْضَعَتْنِي وَأَبَا سَلَمَةَ ثُوَيْبَةُ فَلَا تَعْرِضْنَ عَلَيَّ بَنَاتِكُنَّ وَلَا أَخَوَاتِكُنَّ قَالَ عُرْوَةُ ثُوَيْبَةُ مَوْلَاةٌ لِأَبِي لَهَبٍ كَانَ أَبُو لَهَبٍ أَعْتَقَهَا فَأَرْضَعَتِ النَّبِيَّ ﷺ فَلَمَّا مَاتَ أَبُو لَهَبٍ أُرِيَهُ بَعْضُ أَهْلِهِ فِي النَّوْمِ بِشَرِّ حِيبَةٍ فَقَالَ لَهُ مَاذَا لَقِيتَ؟ فَقَالَ أَبُو لَهَبٍ لَمْ أَلْقَ بَعْدَكُمْ رَخَاءً غَيْرَ أَنِّي سُقِيتُ فِي هَذِهِ مِنِّي بِعَتَاقَتِي ثُوَيْبَةَ وَأَشَارَ إِلَى النَّقِيرَةِ الَّتِي بَيْنَ الْإِبْهَامِ وَالَّتِي تَلِيهَا مِنَ الْأَصَابِعِ  

I said, "O Messenger of Allah ﷺ! Marry my sister, the daughter of Abu Sufyan." He said, "Do you like that?" I said, "Yes, for even now I am not your only wife; and the most beloved person to share the good with me is my sister." The Prophet ﷺ said, "But that is not lawful for me (i.e., to be married to two sisters at a time.)" I said, "O Messenger of Allah ﷺ! By Allah, we have heard that you want to marry Durra, the daughter of Abu Salama." He said, "You mean the daughter of Um Salama?" I said, "Yes." He said, "By Allah ! Even if she were not my stepdaughter, she would not be lawful for me to marry, for she is my foster niece, for Thuwaiba has suckled me and Abu Salama; so you should neither present your daughters, nor your sisters to me." (Using translation from Bukhārī 5107)   

أَنَّ أُمَّ حَبِيبَةَ زَوْجَ النَّبِيِّ ﷺ قَالَتْ يَا رَسُولَ اللهِ انْكِحْ أُخْتِي بِنْتَ أَبِي سُفْيَانَ فَقَالَ رَسُولُ اللهِ ﷺ وَتُحِبِّينَ ذَلِكَ؟ قَالَتْ نَعَمْ لَسْتُ لَكَ بِمُخْلِيَةٍ وَأَحَبُّ مَنْ شَارَكَنِي فِي خَيْرٍ أُخْتِي قَالَتْ فَقَالَ رَسُولُ اللهِ ﷺ فَإِنَّ ذَلِكَ لَا يَحِلُّ لِي قَالَتْ فَقُلْتُ يَا رَسُولَ اللهِ فَوَاللهِ إِنَّا لَنَتَحَدَّثُ أَنَّكَ تُرِيدُ أَنْ تَنْكِحَ دُرَّةَ بِنْتَ أَبِي سَلَمَةَ فَقَالَ رَسُولُ اللهِ ﷺ بِنْتَ أُمِّ سَلَمَةَ؟ قَالَتْ فَقُلْتُ نَعَمْ قَالَ فَوَاللهِ لَوْ لَمْ تَكُنْ رَبِيبَتِي فِي حِجْرِي مَا حَلَّتْ لِي؛ إِنَّهَا ابْنَةُ أَخِي مِنَ الرَّضَاعَةِ أَرْضَعَتْنِي وَأَبَا سَلَمَةَ ثُوَيْبَةُ فَلَا تَعْرِضْنَ عَلَيَّ بَنَاتِكُنَّ وَلَا أَخَوَاتِكُنَّ