Musnad Ahmad 25:304

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, he said: I heard Yahya ibn al-Mujabbar al-Taymi narrating from Salim ibn Abi al-Ja'd, from Ibn Abbas, that a man came to him and said: "What do you say about a man who killed a man intentionally?" He said: "{His recompense is Hell, wherein he will abide eternally, and Allah has become angry with him and has cursed him and has prepared for him a great punishment} [An-Nisa: 93]. It was revealed among the last things that were revealed; nothing abrogated it until the Messenger of Allah (peace and blessings of Allah be upon him) passed away, and no revelation descended after the Messenger of Allah (peace and blessings of Allah be upon him)." He said: "What do you say if he repents, believes, does righteous deeds, and then is guided?" He said: "And how can he have repentance? For I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: 'May his mother be bereaved of him: a man who killed a man intentionally, he will come on the Day of Resurrection, his victim holding him by his right hand or his left hand, and holding his head with his right hand or his left hand, his jugular veins gushing blood toward the Throne, saying: O Lord, ask Your servant for what he killed me?'"