'Chains' in the Bible

And when Herod was about to bring him forth, the same night Peter was sleeping between two soldiers, bound with two chains: and guards before the door kept the prison.

And behold, an angel of the Lord stood by him, and a light shined in the cell: and he smote Peter on the side, and awoke him, saying, Rise up quickly. And his chains fell off from his hands.

Then the chief captain came near, and laid hold on him, and commanded him to be bound with two chains; and inquired who he was, and what he had done.