Sahih Muslim Book 8, Hadith Number 3424.

‘Aisha (Allah be pleased with her) reported that Sahla bint Suhail came to Allah’s Apostle (May peace be upon him) and said: Messenger of Allah, I see on the face of Abu Hudhaifa (signs of disgust) on entering of Salim (who is an ally) into (our house), whereupon Allah’s Apostle (May peace be upon him) said: Suckle him. She said: How can I suckle him as he is a grown-up man? Allah’s Messenger (May peace be upon him) smiled and said: I already know that he is a young man ‘Amr has made this addition in his narration that he participated in the Battle of Badr and in the narration of Ibn ‘Umar (the words are): Allah’s Messenger (May peace be upon him) laughed.