'Seven fold' in the Bible

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.

If Cain is avenged sevenfold,Then Lamech seventy-sevenfold.”

And return to our neighbors sevenfold into their bosomThe reproach with which they have reproached You, O Lord.

But when he is found, he must repay sevenfold;He must give all the substance of his house.