Musannaf Ibn Abi Shayba 18:1

Abu Abd al-Rahman Baqi ibn Makhlad narrated to us, he said: Abu Bakr Abdullah ibn Muhammad ibn Abi Shayba al-Absi narrated to us, he said: Ibn Uyaynah narrated to us, from Amr, from Ikrimah, who said: The Prophet, peace and blessings of Allah be upon him, decreed for a man from the Ansar, whom a freed slave of Banu Adi had killed, the blood money of twelve thousand. And concerning them was revealed: "And they did not resent except that Allah and His Messenger had enriched them of His bounty."