'A'isha (Allah be pleased with her) reported tha Messenger of Allah 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 Messenger of Allah 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? Messenger of Allah 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 ﷺ كَانَ عِنْدَهَا وَإِنَّهَا سَمِعَتْ صَوْتَ رَجُلٍ يَسْتَأْذِنُ فِي بَيْتِ حَفْصَةَ . قَالَتْ عَائِشَةُ فَقُلْتُ يَا رَسُولَ اللَّهِ هَذَا رَجُلٌ يَسْتَأْذِنُ فِي بَيْتِكَ . فَقَالَ رَسُولُ اللَّهِ ﷺ " أُرَاهُ فُلاَنًا " . لِعَمِّ حَفْصَةَ مِنَ الرَّضَاعَةِ . فَقَالَتْ عَائِشَةُ يَا رَسُولَ اللَّهِ لَوْ كَانَ فُلاَنٌ حَيًّا - لِعَمِّهَا مِنَ الرَّضَاعَةِ - دَخَلَ عَلَىَّ قَالَ رَسُولُ اللَّهِ ﷺ " نَعَمْ إِنَّ الرَّضَاعَةَ تُحَرِّمُ مَا تُحَرِّمُ الْوِلاَدَةُ " .