Genesis 4:15
“Not so!” replied the LORD. “If anyone slays Cain, then Cain will be avenged sevenfold.” And the LORD placed a mark on Cain, so that no one who found him would kill him.
Berean 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.
The LORD said to him, “Therefore whoever slays Cain, vengeance will be taken on him sevenfold.” The LORD appointed a sign for Cain, so that anyone finding him would not strike him.