The Book of Marriage (Kitab Al-Nikah)
Muslim :: Book 8 : Hadith 3428
Zainab daughter of Abu Salama reported: 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 (may peace be upon him) 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 (may peace be upon him) 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 Hadhaifa.