Muwatta Imam Malik (Riwayat Ibn al-Qasim)

It is narrated from Ibn Muhairiz (a Tabi'i) that I entered the mosque and saw Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him), then I sat with him and asked about 'azl (withdrawal): So Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) said: We went out with the Messenger of Allah (peace and blessings be upon him) for the battle of Banu al-Mustaliq, and there the women of the Arabs (disbelievers) became our slave girls. We desired women, and being without women was very hard for us, and we also wanted ransom (by selling these women). So we intended to practice 'azl and said: The Messenger of Allah (peace and blessings be upon him) is among us, can we practice 'azl before asking him? Then we asked him (peace and blessings be upon him), and he said: "There is no harm for you in not practicing 'azl, every soul that is to be created until the Day of Judgment will be created."