No Muslim should be killed in , for the killing of (a disbeliever).

1.003.111
Narrated Ash-Sha'bi:
Abu Juhaifa said, "I asked Ali, 'Have you got any book (which has been revealed to the Prophet apart from the Qur'an)?' 'Ali replied, 'No, except Allah's Book or the power of understanding which has been bestowed (by Allah) upon a Muslim or what is (written) in this sheet of paper (with me).' Abu Juhaifa said, "I asked, 'What is (written) in this sheet of paper?' Ali replied, it deals with The Diyya (compensation (blood money) paid by the killer to the relatives of the victim), the ransom for the releasing of the captives from the hands of the enemies, and the law that no Muslim should be killed in Qisas (equality in punishment) for the killing of (a disbeliever).


09.83.50
Narrated Abu Juhaifa:
I asked 'Ali "Do you have anything Divine literature besides what is in the Qur'an?" Or, as Uyaina once said, "Apart from what the people have?" 'Ali said, "By Him Who made the grain split (germinate) and created the soul, we have nothing except what is in the Quran and the ability (gift) of understanding Allah's Book which He may endow a man, with and what is written in this sheet of paper." I asked, "What is on this paper?" He replied, "The legal regulations of Diya (Blood-money) and the (ransom for) releasing of the captives, and the judgment that no Muslim should be killed in Qisas (equality in punishment) for killing a Kafir (disbeliever)."