Musnad Ahmad 32:1098

Yahya ibn Zakariya ibn Abi Za'idah narrated to us, Abu Ayyub al-Ifriqi narrated to us, from Ishaq ibn Abdullah ibn Abi Talha, from Anas ibn Malik, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said on the day of Hunayn: "Whoever singles out a man and kills him, then for him is his spoils." So Abu Talha brought the spoils of twenty-one men.