It was narrated from 'Ikrimah, from Ibn 'Abbas, that :
the Prophet (ﷺ) set the blood money at twelve thousand (Dirham). He said: "This is what Allah says: 'And they could not find any cause to do so except that Allah and his Messenger (ﷺ) had enriched them of His bounty.'" He said: "By their taking the blood money."
English reference: Vol. 3, Book 21, Hadith 2632
Arabic reference: Book 21, Hadith 2734