Musannaf Ibn Abi Shayba 36:363

'Abd al-Rahim ibn Sulayman narrated to us, from Hajjaj, from al-Hakam, from Miqsam, from Ibn 'Abbas: He said: A man took a woman captive on the day of Khaybar, so he carried her behind him. She struggled with him over the hilt of his sword, so he killed her. The Messenger of Allah (may Allah bless him and grant him peace) saw her and said: "Who killed this woman?" They informed him, so he forbade the killing of women.