So the LORD said to him, 'Therefore whoever kills Cain, vengeance will be taken on him sevenfold ' And the LORD appointed a sign for Cain, so that no one finding him would slay him.
(New American Standard Bible)
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.
(King James Version)