Musnad Ahmad 27:1922

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from al-Zuhri, from Salim ibn 'Abd Allah, from Ibn 'Umar, who said: The Prophet, may God bless him and grant him peace, sent Khalid ibn al-Walid to the Banu—I think he said—Jadhima. He invited them to Islam, but they did not know how to say, "We have submitted (aslamna)." So they began saying, "We have changed our religion (saba'na), we have changed our religion (saba'na)." Khalid began taking them captive and killing them. He said: He handed over a captive to each man among us. Then, when a day arrived, Khalid ordered that every man among us should kill his captive. Ibn 'Umar said: I said, "By God, I will not kill my captive, and no man among my companions will kill his captive." He said: Then they came to the Prophet, may God bless him and grant him peace, and mentioned to him what Khalid had done. The Prophet, may God bless him and grant him peace, said—and he raised his hands—"O God, I am innocent before You of what Khalid has done," twice.