Abu Dawud Book 8, Hadith Number 2632.

Narated By Salamah ibn al-Akwa’ : The Apostle of Allah (PBUH) appointed AbuBakr our commander and we fought with some people who were polytheists, and we attacked them at night, killing them. Our war-cry that night was “put to death; put to death.” Salamah said: I killed that night with my hand polytheists belonging to seven houses.