Hadithcore
Hadith #2114720

Ibn ’Abbas (RAA) narrated that, 'A man killed another man during the lifetime of the Prophet (ﷺ), so the Prophet (ﷺ) decided that his Diyah would be 12 thousand (Dirhams).' Related by the four Imams.

عَنْ اِبْنِ عَبَّاسٍ رَضِيَ اَللَّهُ عَنْهُمَا قَالَ: { قَتَلَ رَجُلٌ رَجُلًا عَلَى عَهْدِ اَلنَّبِيِّ ‏- صلى الله عليه وسلم ‏- [1]‏ فَجَعَلَ اَلنَّبِيُّ ‏- صلى الله عليه وسلم ‏-دِيَتَهُ اِثْنَيْ عَشَرَ أَلْفًا } رَوَاهُ اَلْأَرْبَعَةُ, وَرَجَّحَ النَّسَائِيُّ وَأَبُو حَاتِمٍ إِرْسَالَهُ.‏ [2]‏ .‏

References2 variants
Sunnah.com reference
Book 9, Hadith 31
Arabic/English book reference
Book 9, Hadith 1228