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).

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.

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

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.

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.

The above hadith is narratted through other chains except they did not mention 'Azza like the chain of Yazid Bin Abi Habib.

In the narration transmitted on the authority of Ibn Bishr there is a mention of two sucklings and Ibn Abu Shaiba has narrated it with a small variation of wording.

Ahadith like this is transmitted by 'A'isha through another chain of narrators.

Messenger of Allah, Salim (the freed slave of Abu Hudhaifa) is living with us in our house, and he has attained (puberty) as men attain it and has acquired knowledge (of the sex problems) as men acquire, whereupon he said: Suckle him so that he may become unlawful (in regard to marriage) for you He (Ibn Abu Mulaika) said: I refrained from (narrating this hadith) for a year or so on account of fear. I then met al-Qasim and said to him: You narrated to me a hadith which I did not narrate (to anyone) afterwards. He said: What is that? I informed him, whereupon he said: Narrate it on my authority that 'A'isha (Allah be pleased with her) had narrated that to me.

I heard Umm Salama, the wife of Allah's Apostle (may peace be upon himy, saying to 'A'isha: By Allah, I do not like to be seen by a young boy who has passed the period of fosterage, whereupon she ('A'isha) said: Why is it so? Sahla daughter of Suhail came to Allah's Messenger (ﷺ) and said: Allah's Messenger, I swear by Allah that I see in the face of Abu Hudhaifa (the signs of disgust) on account of entering of Salim (in the house), whereupon Allah's Messenger (ﷺ) said: Suckle him. She (Sahla bint Suhail) said: He has a heard. But he (again) said: Suckle him, and it would remove what is there (expression of disgust) on the face of Abu Hudhaifa. She said: (I did that) and, by Allah, I did not see (any sign of disgust) on the face of Abu Hudhaifa.

" And women already married, except those whom your right hands possess (iv. 24)" (i. e. they were lawful for them when their 'Idda period came to an end).

They took captives (women) on the day of Autas who had their husbands. They were afraid (to have sexual intercourse with them) when this verse was revealed:" And women already married except those whom you right hands posses" (iv. 24)

Qatada reported a hadith like this with the same chain of transmitters.

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)."

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.

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.