The Prophet (peace and blessings be upon him) said:
"Indeed, the first cases to be judged between the servants (on the Day of Resurrection) will be those of blood (that is, unjust killing)."
Hadith Referenceصحیح الجامع الصغیر / حرف الألف / 2021
Hadith Gradingالألبانی:صحيح
Hadith Takhrij[ت] عن ابن مسعود. خ – ديات، م - قسامة.