Iyas bin Salamah (may Allah have mercy on him) narrates from his father, Sayyiduna Salamah (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) appointed Sayyiduna Abu Bakr (may Allah be pleased with him) as our commander in a campaign against the polytheists. We attacked them at night and killed them, and our watchword that night was 'Amit, amit' (Kill, kill). Sayyiduna Salamah (may Allah be pleased with him) said: That night I killed with my own hand the members of seven households of the polytheists.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18096