Surah An-Nisa Verse 92

611 Life is absolutely sacred in the Islamic Brotherhood. But mistakes will sometimes happen, as did happen in the melee at Uhud, when some Muslims were killed (being mistaken for the enemy) by Muslims. There was no guilty intention: therefore there was no murder. But all the same, the family of the deceased was entitled to compensation unless they freely remitted it, and in addition it was provided that the unfortunate man who made the mistake should free a believing slave. Thus a deplorable mistake was made the occasion for winning the liberty of a slave who was a Believer, for Islam discountenances slavery. The compensation could only be paid if the deceased belonged to a Muslim society or to some people at peace with the Muslim society. Obviously it could not be paid if, though the deceased was a Believer, his people were at war with the Muslim society; even if his people could be reached, it is not fair to increase the resources of the enemy. If the deceased was himself an enemy at war, obviously the laws of war justify his being killed in warfare unless he surrendered. If the man who took life unintentionally has no means from which to free a believing slave or to give compensation, he must still by an act of strict self-denial (fasting for two whole months running) show that he is cognizant of the grave nature of the deed he has done and sincerely repentant I take this to apply to all three cases mentioned: that is, where a Believer killed a Believer unintentionally and the deceased (1} belonged to the same community as you, or (2) belonged to a community at war with you, or (5) belonged to a community in alliance with you.