Musnad Ahmad 31:512

Yahya narrated to us, Hisham narrated to us, Yahya narrated to us, from Muhammad ibn Abd al-Rahman ibn Thawban, who said: Abu Rifa'ah narrated to me, that Abu Sa'id said: A man said to the Messenger of Allah, peace and blessings of Allah be upon him: "I have a slave woman, and I practice *'azl* (coitus interruptus) with her, and I dislike that she should become pregnant, and the Jews claim that it is the 'minor female infanticide' (al-maw'udah al-sughra)." He said: "The Jews have lied. If Allah willed to create him, you would not be able to prevent it."