‘Ikrima told that when some heretics were brought to ‘Ali he had them burned, and that when Ibn ‘Abbas heard of it he said that if it had been he, he would not have had them burned because of God’s Messenger's prohibition, “Do not inflict God’s punishment on anyone”, but would have had them killed on account of the statement made by God’s Messenger, “Kill those who change their religion.”
‘Ali told that he heard God’s Messenger say, “In the last time people will come forth, young and foolish, speaking the finest words men speak, but their faith will not pass their throats. They will come out from the religion as an arrow does from the animal it is aimed at. Wherever you meet them kill them, for a reward for killing them will be given on the day of resurrection to those who kill them.”
Rafi‘ b. Khadij said that one of the Ansar was killed at Khaibar and his relatives went to the Prophet and mentioned that to him. He asked, “Have you two witnesses who can testify to the murderer of your friend?" They replied, “Messenger of God, there was not a single Muslim present, but only Jews who sometimes have the audacity to do even greater crimes than this “He said, “Then choose fifty of them and demand that they take an oath;" but they refused and God’s Messenger paid his blood wit himself.