Musnad Abu Ya'la al-Mawsili 42:333

Zuhayr narrated to us, Yazid bin Harun narrated to us, Hisham bin Hassan informed us, from Muhammad bin Sirin, from his brother Ma'bad bin Sirin, who said: We said to Abu Sa'id al-Khudri, "Did you hear anything from the Messenger of Allah, may Allah bless him and grant him peace, regarding *al-'azl* (coitus interruptus)?" He said, "We asked the Messenger of Allah, may Allah bless him and grant him peace, about *al-'azl*." He said, "And what is *al-'azl*?" We said, "A man has a wife who is breastfeeding, and he has intercourse with her, but he dislikes that she should become pregnant, so he practices *al-'azl* with her. And he has a slave woman and he has intercourse with her, but he dislikes that she should become pregnant, so he practices *al-'azl* with her." The Messenger of Allah, may Allah bless him and grant him peace, said, "It does not harm you not to do that, for it is only the decree."