The Ruling on the Intentional Killing of a Believer and His Repentance

Question:
He says: Honorable Shaykh, may Allah grant you success, regarding the one who is in the Fire, whether or not retaliation (qisas) is carried out against him?

Answer:
In any case, the killer is afflicted with a major sin among the major sins, but it is less than shirk (associating partners with Allah). The major sin that is less than shirk is subject to the will of Allah; if Allah wills, He forgives him, and if He wills, He punishes him. Allah the Exalted said: And killing is less than shirk, so it falls under the category of "what is less than that." The majority of scholars hold that if he repents, Allah accepts his repentance.
Except for Ibn Abbas and some of the Companions, who said that his repentance is not accepted, meaning that he must be punished. However, this does not mean that he is a disbeliever in their view; rather, it means that the warning must be carried out against him, but he will not remain in the Fire forever. This is the view of Ibn Abbas. As for the majority, they say he is like the others who commit major sins less than shirk: if he repents, Allah accepts his repentance. This is because Allah, Glorified and Exalted is He, says: Whoever believes except for those who repent and believe and do righteous deeds; for those, Allah will replace their evil deeds with good ones. And Allah is Forgiving and Merciful. It was mentioned that if he repents, (peace and blessings be upon him) is like the disease that is believed in. So if Allah accepts the repentance of a polytheist, how can repentance not be accepted for killing, which is less than shirk?
This is the evidence of the majority. As for Ibn Abbas (may Allah be pleased with him), the well-known view attributed to him is that his repentance is not accepted, meaning that he must be punished, but he will not remain in the Fire forever. He is punished for his sin but does not remain in the Fire forever. This is the result of the disagreement between Ibn Abbas and the majority. The correct view, without doubt, is the well-known view of the majority. Imam Ibn al-Qayyim (may Allah have mercy on him) in *Al-Jawab al-Kafi* (The Sufficient Answer).
He said: Intentional killing and aggression involve three rights: a right for Allah, a right for the heirs of the victim, and a right for the victim. As for the right of Allah, it is dropped by repentance. As for the right of the heirs of the victim, it is dropped either by their pardon, or by retaliation, or by the payment of blood money (diyah) or pardon. The right of the victim remains upon the killer until the Day of Resurrection. Allah will compensate him with whatever He wills from His bounty and will accept the repentance of the killer.