Musannaf Ibn Abi Shayba 20:77

Ibn ‘Ulayyah narrated to us, from Ayyub, from Muhammad, that when the Prophet, peace and blessings of Allah be upon him, awarded the child to the son of Zam’ah, he said to Sawdah, "Observe hijab (seclusion) from him." And he said, "If I had not done this, no man would have wished to claim the child of another man except that he would have claimed him."