Sahih Muslim 1444 a
'A'isha (Allah be pleased with her) reported tha Allah's Messenger (ﷺ) was with her and she heard the voice of a person seeking permission to enter the house of Hafsa. 'A'isha (Allah he pleased with her) said:
Allah's Messenger, he is the person who seeks permission to enter your house, whereupon Allah's Messenger (ﷺ) said: I think he is so and so (uncle of Hafsa by reason of fosterage). 'A'isha said: Messenger of Allah, if so and so (her uncle by reason of fosterage) were alive, could he enter my house? Allah's Messenger (ﷺ) said: Yes. Fosterage makes unlawful what consanguinity makes unlawful.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَكْرٍ، عَنْ عَمْرَةَ، أَنَّ عَائِشَةَ، أَخْبَرَتْهَا أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ عِنْدَهَا وَإِنَّهَا سَمِعَتْ صَوْتَ رَجُلٍ يَسْتَأْذِنُ فِي بَيْتِ حَفْصَةَ ‏.‏ قَالَتْ عَائِشَةُ فَقُلْتُ يَا رَسُولَ اللَّهِ هَذَا رَجُلٌ يَسْتَأْذِنُ فِي بَيْتِكَ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ أُرَاهُ فُلاَنًا ‏"‏ ‏.‏ لِعَمِّ حَفْصَةَ مِنَ الرَّضَاعَةِ ‏.‏ فَقَالَتْ عَائِشَةُ يَا رَسُولَ اللَّهِ لَوْ كَانَ فُلاَنٌ حَيًّا - لِعَمِّهَا مِنَ الرَّضَاعَةِ - دَخَلَ عَلَىَّ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ نَعَمْ إِنَّ الرَّضَاعَةَ تُحَرِّمُ مَا تُحَرِّمُ الْوِلاَدَةُ ‏"‏ ‏.‏