Aflah asked the permission to visit me but I did not allow him. He said, "Do you veil yourself before me although I am your uncle?" ʿAisha said, "How is that?" Aflah replied, "You were suckled by my brother's wife with my brother's milk." I asked Messenger of Allah ﷺ about it, and he said, "Aflah is right, so permit him to visit you."

قَالَتِ اسْتَأْذَنَ عَلَىَّ أَفْلَحُ فَلَمْ آذَنْ لَهُ فَقَالَ أَتَحْتَجِبِينَ مِنِّي وَأَنَا عَمُّكِ فَقُلْتُ وَكَيْفَ ذَلِكَ قَالَ أَرْضَعَتْكِ امْرَأَةُ أَخِي بِلَبَنِ أَخِي فَقَالَتْ سَأَلْتُ عَنْ ذَلِكَ رَسُولَ اللَّهِ ﷺ فَقَالَ صَدَقَ أَفْلَحُ ائْذَنِي لَهُ

The Prophet ﷺ said about Hamza's daughter, "I am not legally permitted to marry her, as foster relations are treated like blood relations (in marital affairs). She is the daughter of my foster brother."

قَالَ النَّبِيُّ ﷺ فِي بِنْتِ حَمْزَةَ لاَ تَحِلُّ لِي يَحْرُمُ مِنَ الرَّضَاعِ مَا يَحْرُمُ مِنَ النَّسَبِ هِيَ بِنْتُ أَخِي مِنَ الرَّضَاعَةِ

Aishah, the Prophet’s ﷺ wife, reported that the Messenger of Allah ﷺ was with her, and that she heard the voice of a man asking permission to enter at Hafsah’s house. Aishah said: “So I said, O Messenger of Allah, I think it is so-and-so, the foster-uncle of Hafsah.” Aishah said: “O Messenger of Allah, this is a man asking permission to enter your house.” She said: The Messenger of Allah ﷺ said: “I think it is so-and-so, the foster-uncle of Hafsah.”

Aishah said: “If so-and-so were alive, her foster-uncle, he would have been allowed to enter upon me?” The Messenger of Allah ﷺ said: “Yes. Indeed, breastfeeding makes unlawful what birth makes unlawful.”

أَنَّ عَائِشَةَ ؓ، زَوْجَ النَّبِيِّ ﷺ، أَخْبَرَتْهَا أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ عِنْدَهَا، وَأَنَّهَا سَمِعَتْ صَوْتَ رَجُلٍ يَسْتَأْذِنُ فِي بَيْتِ حَفْصَةَ. قَالَتْ عَائِشَةُ: فَقُلْتُ، يَا رَسُولَ اللَّهِ، أُرَاهُ فُلَانًا لِعَمِّ حَفْصَةَ مِنَ الرَّضَاعَةِ. قَالَتْ عَائِشَةُ: يَا رَسُولَ اللَّهِ، هَذَا رَجُلٌ يَسْتَأْذِنُ فِي بَيْتِكَ. قَالَتْ: فَقَالَ رَسُولُ اللَّهِ ﷺ: «أُرَاهُ فُلَانًا لِعَمِّ حَفْصَةَ مِنَ الرَّضَاعَةِ».

فَقَالَتْ عَائِشَةُ: لَوْ كَانَ فُلَانٌ حَيًّا، لِعَمِّهَا مِنَ الرَّضَاعَةِ، دَخَلَ عَلَيَّ؟ فَقَالَ رَسُولُ اللَّهِ ﷺ: «نَعَمْ، إِنَّ الرَّضَاعَةَ تُحَرِّمُ مَا يَحْرُمُ مِنَ الْوِلَادَةِ».

Once the Prophet ﷺ came to me while a man was in my house. He said, "O ʿAisha! Who is this (man)?" I replied, "My foster brothers" He said, "O ʿAisha! Be sure about your foster brothers, as fostership is only valid if it takes place in the suckling period (before two years of age).

دَخَلَ عَلَىَّ النَّبِيُّ ﷺ وَعِنْدِي رَجُلٌ قَالَ يَا عَائِشَةُ مَنْ هَذَا قُلْتُ أَخِي مِنَ الرَّضَاعَةِ قَالَ يَا عَائِشَةُ انْظُرْنَ مَنْ إِخْوَانُكُنَّ فَإِنَّمَا الرَّضَاعَةُ مِنَ الْمَجَاعَةِ