Acts 5:23

Saying, the prison truly found we shut with all safety,
&c.] Locked, barred and bolted;

and the keepers standing without before the doors;
both inner and outer in their proper places, diligently discharging their office:

but when we had opened we found no man within;
that is, none of the apostles, for there might be other prisoners in it, who were not released by this means.