سنن النسائي

It was narrated from Ibn 'Abbas that: The Prophet (ﷺ) [SAW] said: "The slain will bring his killer on the Day of Resurrection with his forelock and his head in his hand, and with his jugular veins flowing with blood, and will say: 'O Lord, he killed me,' until he draws near to the Throne." They mentioned repentance to Ibn 'Abbas and he recited this Verse: "And whoever kills a believer intentionally, his recompense is Hell" He said: "It has not been abrogated since it was revealed; there is no way he could repent."