seeing your pure behavior in fear.
What is he talking about? The prison was death by which men were bound. They were held captive. Jesus came to open the prison to those that are bound, or to open up Hades to those people who were bound there, who died before Jesus died for our sins. So when He died, He descended into hell. And He preached to those souls that were in prison. And when He ascended out of hell, He brought with Him those who had been captive.