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.

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

The above hadith is narrated through another chain.

'A'isha (Allah be pleased with her) reported that Aflah, the brother of Abu'l-Qu'ais, who was her uncle by reason of fosterage, came, and asked her permission (to enter the house) after seclusion (Hijab) was instituted. I refused to admit him. When Allah's Messenger (ﷺ) came, I informed him what I had done. He commanded me to grant him permission (as the brother of her foster-father was also her uncle).

There came to me Aflah b. Abu Qulais, my uncle by reason of fosterage; the rest of the hadith is the same (but with this) addition:" I ('A'isha) said (to the Holy Prophet): It was the woman who suckled me and not the man, whereupon he (Allah's Messenger) said: May your hands or your right hand be besmeared with dust (you were mistaken)."

By Allah, I would not permit Aflah unless I have solicited the opinion of Allah's Messenger (ﷺ) for Abu Qulais has not suckled me, but his wife has given me suck. 'A'isha' (Allah be pleased with her) said: When Allah's Messenger (ﷺ) entered, I said: Allah's Messenger, Aflah is the brother of Abu'l-Qulais; he came to me to seek my permission for entering (the houst). I did not like the idea of granting him permission until I had solicited your opinion. Thereupon Allah's Apostle (ﷺ) said: Grant him permission. 'Urwa said it was on account of this that 'A'isha used to say. What is unlawful by reason of consanguinity is unlawful by reason of fosterage.

There came Aflah, the brother of Abu'l Qulais (Allah be pleased with him), and sought permission from her, the rest of the hadith is the same (except for the words that the Holy Prophet) said:" He is your uncle. Let your hand be besmeared with dust. Abu'l Qulais was the husband of the woman who had suckled 'A'isha (Allah be pleased with her).

My foster uncle came to me and sought permission (to enter the house), but I refused him permission until I had solicited the opinion of Allah's Messenger (ﷺ). When Allah's Messenger (ﷺ) came, I said to him: My foster-uncle sought my permission to (enter the house), but I did not permit him, whereupon Allah's Messenger (ﷺ) said: You better admit your uncle (into the house). I ('A'isha) said: It was the woman who suckled me and not the man. (But he) said: He is your uncle, admit him.

" The brother of Abu'l-Qu'ais sought permission from her ('A'isha) (to enter the house). The rest is the same.

This hadith has been narrated on the authority of Hisham with the same chain of transmitters but with a slight variation of words.

My foster-uncle Abu'l Ja'd (kunya of Aflah) sought permission from me, which I refused. (Hisham said to me that Abu'l-Ja'd was in fact Abu'l-Qu'ais). When Allah's Apostle (ﷺ) came, I ('A'isha) informed him about it. He said: Why did you not permit him? Let your right hand or hand be besmeared with dust.

Don't observe veil from him for he is Mahram (one with whom marriage cannot be contracted) on account of fosterage as one is Mahram on account of consanguinity.

Aflah b. Qu'ais sought permission from me (to enter the house), but I refused to grant him the permission, and he sent me (the message saying): I am your uncle (in the sense) that the wife of my brother has suckled you, (but still) I refused to grant him permission. There came the Messenger of Allah (ﷺ) and I made a mention of it to him, and he said: He can enter (your house), for he is your uncle.

Messenger of Allah, why is it that you select (your wife) from among the Quraish, but you ignore us (the nearest of the kin)? Thereupon he said: Have you anything for me (a suitable match for me)? I said; Yes, the daughter of Hamza, whereupon Allah's Messenger (ﷺ) said: She is not lawful for me, for she is the daughter of my brother by reason of fosterage.

A hadith like this has been narrated on the authority of A'mash with the same chain of transmitters.

It was proposed that he (the Holy Prophet) be married to the daughter of Hamza, whereupon he said: She is not lawful for me for she is the daughter of my foster-brother, and that is unlawful by reason of fosterage what is unlawful by reason of genealogy.

A hadith like this is narrated on the authority of Hammam, Sa'id, Bishr b 'Umar, but with a small variation of words.

It was said to the Messenger of Allah (ﷺ): Is not the daughter of Hamza a suitable match for you? Or it was said: Why don't you propose to marry the daughter of Hamza, the son of Abd al-Muttalib? Thereupon he said: Hamza is my brother by reason of fosterage.

The Messenger of Allah (ﷺ) came to me and I said to him: Have you any inclination towards my the daughter of Abu Sufyan? He (the Holy Prophet) said: Then what should I do? I said: Marry her. He said: Do you like that? I said: I am not the exclusive (wife) of yours; I, therefore, wish to join my sister in good. He, said: She is not lawful for me. I said: I have been informed that you have given the proposal of marriage to Durrah daughter of Abu Salama He raid: You mean the daughter of Umm Salama? I said: Yes. He said: Even if she had not been my step-daughter brought up under my guardianship, she would not have been lawful for me, for she is the daughter of my foster-brother (Hamza), for Thuwaiba had suckled me and her father. So do not give me the proposal of the marriage of your daughters and sisters.