Musannaf Ibn Abi Shayba 36:302

Yahya ibn Ishaq narrated to us, he said: Yahya ibn Ayyub informed us, he said: Rabi'ah ibn Abi Abd al-Rahman narrated to me, from Muhammad ibn Yahya ibn Habban, from Ibn Muhayriz, who said: I and Abu Sirmah al-Mazini entered upon Abu Sa'id al-Khudri, and we asked him about *al-'azl* (coitus interruptus). He said: We captured noble women of the Arabs; we captured women of the Banu al-Mustaliq, and we desired *al-'azl* and we desired the ransom. Some of us said: "Will you practice *al-'azl* while the Messenger of Allah, peace and blessings of Allah be upon him, is among you?" So we came to him and said: "O Messenger of Allah, we captured noble women of the Arabs; we captured women of the Banu al-Mustaliq, and we desired *al-'azl* and we desired the ransom." The Prophet, peace and blessings of Allah be upon him, said: "It does not matter if you do not do it, for there is no soul that Allah has written to exist until the Day of Resurrection, but it will surely exist."