Never should a believer kill a believer; but (If it so happens) by mistake, (Compensation is due): If one (so) kills a believer, it is ordained that he should free a believing slave, and pay compensation to the deceased's family, unless they remit it freely. If the deceased belonged to a people at war with you, and he was a believer, the freeing of a believing slave (Is enough). If he belonged to a people with whom ye have treaty of Mutual alliance, compensation should be paid to his family, and a believing slave be freed. For those who find this beyond their means, (is prescribed) a fast for two months running: by way of repentance to God: for God hath all knowledge and all wisdom. (4:92)

They are the ones who denied Revelation and hindered you from the Sacred Mosque and the sacrificial animals, detained from reaching their place of sacrifice. Had there not been believing men and believing women whom ye did not know that ye were trampling down and on whose account a crime would have accrued to you without (your) knowledge, (God would have allowed you to force your way, but He held back your hands) that He may admit to His Mercy whom He will. If they had been apart, We should certainly have punished the Unbelievers among them with a grievous Punishment. (48:25)