Yahya related to me from Malik from Nafi from Ibn Umar that theMessenger of Allah, may Allah bless him and grant him peace, saw thecorpse of a woman who had been slain in one of the raids, and hedisapproved of it and forbade the killing of women and children. (ID)
USC-MSA web (English) reference: Book 21, Hadith 9 (ID)
Arabic reference (ID): Book 21, Hadith 970 (ID)