from Ibn 'Abbas that the Prophet ﷺ made the blood-money twelve thousand.  

عَنِ النَّبِيِّ ﷺ أَنَّهُ جَعَلَ الدِّيَةَ اثْنَىْ عَشَرَ أَلْفًا  

(Another chain) from 'Ikrimah from the Prophet ﷺ and it is similar but he did not mention "from Ibn 'Abbas" in it. There is much more criticism than this for (this) narration of Ibn 'Uyainah.  

عَنِ النَّبِيِّ ﷺ نَحْوَهُ وَلَمْ يَذْكُرْ فِيهِ عَنِ ابْنِ عَبَّاسٍ وَفِي حَدِيثِ ابْنِ عُيَيْنَةَ كَلاَمٌ أَكْثَرُ مِنْ هَذَا