Charles Spurgeon Commentary Acts 16:28

"But Paul cried with a loud voice, saying, Do thyself no harm: for we are all here." — Acts 16:28 (ASV)

Every prisoner was released from his chains, but not one had escaped; nor had anyone even attempted to escape, which was another miracle; for men who see their chains broken and the prison doors open are very likely to run away. These men did not, for a heavenly charm was upon them. They kept in their cells, so that Paul could cry out to the jailer, "Do thyself no harm: for we are all here."