So when you meet in battle those who disbelieve, then smite the necks until when you have overcome them, then make (them) prisoners, and afterwards either set them free as a favor or let them ransom (themselves) until the war terminates. That (shall be so); and if Allah had pleased He would certainly have exacted what is due from them, but that He may try some of you by means of others; and (as for) those who are slain in the way of Allah, He will by no means allow their deeds to perish.

Allah sets forth an example to those who disbelieve the wife of Nuh and the wife of Lut: they were both under two of Our righteous servants, but they acted treacherously towards them so they availed them naught against Allah, and it was said: Enter both the fire with those who enter.