Genesis 4:12-15 NIV

[12] When you work the ground, it will no longer yield its crops for you. You will be a restless wanderer on the earth.” [13] Cain said to the LORD, “My punishment is more than I can bear. [14] Today you are driving me from the land, and I will be hidden from your presence; I will be a restless wanderer on the earth, and whoever finds me will kill me.” [15] But the LORD said to him, “Not so; anyone who kills Cain will suffer vengeance seven times over.” Then the LORD put a mark on Cain so that no one who found him would kill him.