Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates that on the day of Khaybar, we reached the slave women, and we used to practice 'azl (withdrawal) with them, and we were searching to see if any of their families would pay their ransom. So some of us said to others, "You are doing this while the Messenger of Allah (peace and blessings be upon him) is among you?" So we came to the Prophet (peace and blessings be upon him) and mentioned this before him. He (peace and blessings be upon him) said: "Not every drop of water (semen) produces a child. When Allah decides a matter, it happens." He said that the Prophet (peace and blessings be upon him) passed by some pots that were boiling, and he (peace and blessings be upon him) asked: "What meat is this?" We said: "Donkey meat." He asked: "Domestic or wild?" We said: "No, rather domestic." He (peace and blessings be upon him) said to us: "Pour it out." So we poured it out, and indeed we were hungry and desired it. He said: "And we were commanded to tie the mouths of the water skins with a rope."