The Messenger of Allah ﷺ was with her, and she heard the voice of a man seeking permission to enter the house of Hafsah. Aishah said: I said, “O Messenger of Allah, this is a man seeking permission to enter your house.” The Messenger of Allah ﷺ said: “I think he is so-and-so, Hafsah’s paternal uncle through breastfeeding.”

Aishah said: “O Messenger of Allah, if so-and-so were alive, her paternal uncle through breastfeeding, would he be allowed to enter upon me?” The Messenger of Allah ﷺ said: “Yes. Indeed, breastfeeding makes unlawful what birth makes unlawful.”

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 فُلَانًا لِعَمِّ حَفْصَةَ مِنَ الرَّضَاعَةِ».

فَقَالَتْ عَائِشَةُ: يَا رَسُولَ اللَّهِ، لَوْ كَانَ فُلَانٌ حَيًّا، لِعَمِّهَا مِنَ الرَّضَاعَةِ، دَخَلَ عَلَيَّ؟ قَالَ رَسُولُ اللَّهِ ﷺ: «نَعَمْ، إِنَّ الرَّضَاعَةَ تُحَرِّمُ مَا تُحَرِّمُ الْوِلَادَةُ».

"What becomes unlawful through breastfeeding is that which becomes unlawful through birth."

لِي رَسُولُ اللَّهِ ﷺ يَحْرُمُ مِنَ الرَّضَاعَةِ مَا يَحْرُمُ مِنَ الْوِلاَدَةِ

The above hadith is narrated through another chain.

أَخْبَرَنِي عَبْدُ اللَّهِ بْنُ أَبِي بَكْرٍ بِهَذَا الإِسْنَادِ مِثْلَ حَدِيثِ هِشَامِ بْنِ عُرْوَةَ