Marriage (Kitab Al-Nikah)
Dawud :: Book 11 : Hadith 2153
Narrated Ruwayfi' ibn Thabit al-Ansari:
Should I tell you what I heard the Apostle of Allah (peace_be_upon_him) say on the day of Hunayn: It is not lawful for a man who believes in Allah and the last day to water what another has sown with his water (meaning intercourse with women who are pregnant); it is not lawful for a man who believes in Allah and the Last Day to have intercourse with a captive woman till she is free from a menstrual course; and it is not lawful for a man who believes in Allah and the Last Day to sell spoil till it is divided.