Musannaf Ibn Abi Shayba 28:554

Abu Mu'awiyah narrated to us, from Abu Malik al-Ashja'i, from Nu'aym ibn Abi Hind, from the son of Samurah ibn Jundub, from his father, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever kills [an enemy], then for him is his spoils (al-salab)."