Charles Ellicott Commentary Acts 5:18

"and laid hands on the apostles, and put them in public ward." — Acts 5:18 (ASV)

Put them in the common prison.—The word is the same as the ward of Acts 4:3. The addition of the word “common” or “public” perhaps indicates a greater severity of treatment. They were not merely kept in custody, but dealt with as common criminals, compelled to herd with ruffians and robbers and murderers.