Abu 'Alqama أبو علقمة · The Book of Marriage

"Why do you do that?" We said: "A man may have a wife, and he has intercourse with her, but he does not want her to get pregnant, or he may have a concubine, and he has intercourse with her, but he does not want her to get pregnant." He said: "It does not make any difference if you do that, for it is the matter of Al-Qadr."