'Chains' in the Bible

and when Herod was about to bring him forth, the same night was Peter sleeping between two soldiers, having been bound with two chains, guards also before the door were keeping the prison,

and lo, a messenger of the Lord stood by, and a light shone in the buildings, and having smitten Peter on the side, he raised him up, saying, 'Rise in haste,' and his chains fell from off his hands.

Then the chief captain, having come nigh, took him, and commanded him to be bound with two chains, and was inquiring who he may be, and what it is he hath been doing,