Genesis 4:15

And the Lord God said to him, Not so, any one that slays Cain shall suffer sevenfold vengeance; and the Lord God set a mark upon Cain that no one that found him might kill him.

And the Lord said unto him, Therefore whosoever slayeth Cain, vengeance shall be taken on him sevenfold. And the Lord set a mark upon Cain, lest any finding him should kill him.

Yahweh said to him, “Therefore whoever slays Cain, vengeance will be taken on him sevenfold.” Yahweh appointed a sign for Cain, so that anyone finding him would not strike him.