Narrated A'isha 'Sahlah bint Suhail came to the Prophet (saw) and said 'O Messenger of Allah (swt), I see signs of displeasure on the face of Abo Hudhaifah when Salim enters upon me', The Prophet (saw) said: "Breastfeed him!", She said: "How can I breastfeed him when he is a grown man!?" The messenger of Allah (swt) smiled and said 'I know that he is a grown man!'. So she did that, then she came to the Prophet (saw) and said "I have never seen any signs of displeasure on the face of Abo Hudhayfah after that. And he was present at the battle of Badar.
Hadith is sahih, (authentic)
Footnote: Due to this hadith, A'isha had the opinion that the milk, in what ever age it is suckled, will prove the prohibition of fosterafe. But the other Mothers of believers did not agree..
Ref: Sunnah Ibn Majah, chapter. 36, hadithnumber 1943, page 113.
Umm Salama said to 'A'isha: 'A young boy who is at the threshold of puberty comes to you. I, however, do not like that he should come to me, whereupon 'A'isha (Allah be pleased with her) said: Don't you see in Allah's Messenger (may peace be upon him) a model for you? She also said: The wife of Abu Hudhaifa said: Messenger of Allah, Salim comes to me and now he is a (grown-up) person, and there is something that (rankles) in the mind of Abu Hudhaifa about him, whereupon Allah's Messenger (may peace be upon him) said: Suckle him (so that he may become your foster-child), and thus he may be able to come to you (freely).
Ref: Sahih Muslim, book 8, hadithnumber 3426, page 846.
...A'isha took that as a precedent for whatever men she wanted to be able to come to see her. She ordered daughters of her sisters and brothers to give milk to whichever men she wanted to be able to come in to see her. The rest of the wives of the Prophet, may Allah bless him and grant him peace, refused to let anyone come in to them by such nursing. They said, 'No! By Allah! We think that what the Messenger of Allah, may Allah bless him and grant him peace, ordered Sahla bint Suhayl to do was only an indulgence concerning the nursing of Salim alone. No! By Allah! No one will come in upon us by such nursing!'
Hadith is sahih, (authentic)
Ref: Musnad Ahmad bin Hanbal, page 192, hadithnumber 26208.
It was related that Umm Salama, the wife of the Messenger of Allah (pbuh) said "All the wives of the Messenger of Allah (saw) refuted the idea that someone who had been fostered in such a way should be permitted to enter their houses, and they told 'A'isha: "By God we see that this was only a conession which the Messenger of Allah (pbu) gave to Salim, but no one will be permitted to enter our houses through such a fosterage and we do not support such a opinion".
Ref: Mokhtaser Sahih Muslim, volume 2, page 489 and 490, hadithnumber 881.
“A'isha opined that adult breast feeding makes an individual mahram, and she practically breast fed a young man, and he would enter upon her, but the remainder mothers of the believers denied it (adult breast feeding) ...”
Ref: 'Fatah ul-Mun’im Sharh Sahih Muslim', volume 5, page 622.