Genesis 4:13-15

13Cain said to the Lord, ‘That punishment is too much! It will give me too much pain.

14Now you are making me leave my home here on the land. I will be far away from where you are. I will be a traveller without a home. If someone sees me, they will kill me.’

15But the Lord said to Cain, ‘No! If anyone kills Cain, I will punish that person seven times more than I have punished you.’ Then the Lord put a special mark on Cain. This was to tell other people that they must not kill Cain.