Musnad Ahmad 1153:99

Sufyan narrated to us, from Abd al-Rahman ibn al-Qasim, from al-Qasim, from Aisha: Sahlah bint Suhayl came and said, "O Messenger of Allah, I see in the face of Abu Hudhayfah [signs of dislike] regarding the entry of Salim upon me." He said, "Breastfeed him." She said, "How shall I breastfeed him when he is a grown man?" The Messenger of Allah, peace and blessings of Allah be upon him, laughed and said, "Do I not know that he is a grown man?" Then she came and said, "I have not seen anything in the face of Abu Hudhayfah that I dislike."