Umm Habibah bint al-Irbad narrated from her father, Sayyiduna al-Irbad bin Sariyah (may Allah be pleased with him), that on the day of Khaybar the Prophet (peace and blessings be upon him) forbade every predatory animal with fangs and every bird with talons; he forbade the mujaththamah (an animal tied up and used as a target); and he forbade having intercourse with pregnant (captive) women until they had delivered what was in their wombs.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15739