Genesis 4:13-16

Cain said to the LORD, “My punishment is more than I can bear. 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.” 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. So Cain went out from the LORD’s presence and lived in the land of Nod, east of Eden.