Sahih al-Bukhari 5101
Narrated Um Habiba:
(daughter of Abu Sufyan) I said, "O Allah's Messenger (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."
حَدَّثَنَا الْحَكَمُ بْنُ نَافِعٍ، أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ أَخْبَرَنِي عُرْوَةُ بْنُ الزُّبَيْرِ، أَنَّ زَيْنَبَ ابْنَةَ أَبِي سَلَمَةَ، أَخْبَرَتْهُ أَنَّ أُمَّ حَبِيبَةَ بِنْتَ أَبِي سُفْيَانَ أَخْبَرَتْهَا أَنَّهَا، قَالَتْ يَا رَسُولَ اللَّهِ انْكِحْ أُخْتِي بِنْتَ أَبِي سُفْيَانَ فَقَالَ ‏"‏ أَوَتُحِبِّينَ ذَلِكَ ‏"‏‏.‏ فَقُلْتُ نَعَمْ، لَسْتُ لَكَ بِمُخْلِيَةٍ، وَأَحَبُّ مَنْ شَارَكَنِي فِي خَيْرٍ أُخْتِي‏.‏ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ إِنَّ ذَلِكَ لاَ يَحِلُّ لِي ‏"‏‏.‏ قُلْتُ فَإِنَّا نُحَدَّثُ أَنَّكَ تُرِيدُ أَنْ تَنْكِحَ بِنْتَ أَبِي سَلَمَةَ‏.‏ قَالَ ‏"‏ بِنْتَ أُمِّ سَلَمَةَ ‏"‏‏.‏ قُلْتُ نَعَمْ‏.‏ فَقَالَ ‏"‏ لَوْ أَنَّهَا لَمْ تَكُنْ رَبِيبَتِي فِي حَجْرِي مَا حَلَّتْ لِي إِنَّهَا لاَبْنَةُ أَخِي مِنَ الرَّضَاعَةِ، أَرْضَعَتْنِي وَأَبَا سَلَمَةَ ثُوَيْبَةُ فَلاَ تَعْرِضْنَ عَلَىَّ بَنَاتِكُنَّ وَلاَ أَخَوَاتِكُنَّ ‏"‏‏.‏ قَالَ عُرْوَةُ وَثُوَيْبَةُ مَوْلاَةٌ لأَبِي لَهَبٍ كَانَ أَبُو لَهَبٍ أَعْتَقَهَا فَأَرْضَعَتِ النَّبِيَّ صلى الله عليه وسلم فَلَمَّا مَاتَ أَبُو لَهَبٍ أُرِيَهُ بَعْضُ أَهْلِهِ بِشَرِّ حِيبَةٍ قَالَ لَهُ مَاذَا لَقِيتَ قَالَ أَبُو لَهَبٍ لَمْ أَلْقَ بَعْدَكُمْ غَيْرَ أَنِّي سُقِيتُ فِي هَذِهِ بِعَتَاقَتِي ثُوَيْبَةَ‏.‏