It is narrated from Hazrat Ruwaifi’ (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "It is not lawful for any person to irrigate (i.e., have intercourse with) another's child with his water (i.e., semen), and no man should have intercourse with a slave woman until she has her menstrual period or it becomes clear that she is pregnant."