17:12 To prevent all possibility of release, Peter had been put under the charge of sixteen soldiers, who, in different watches, guarded him day and night. In his cell he was placed between two soldiers and was bound by two chains, each chain being fastened to the wrist of one of the soldiers. He was unable to move without their knowledge. With the prison doors securely fastened, and a strong guard before them, all chance of rescue or escape through human means was cut off. But man's extremity is God's opportunity.