Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "Indeed, Allah smiles at two men, one of whom has killed the other, yet both will enter Paradise. One person participates in jihad in the way of Allah and is martyred, then Allah grants the killer the ability to repent (he becomes a Muslim), and then he too participates in jihad in the way of Allah and is martyred."