Albert Barnes Commentary Acts 23:35

"I will hear thee fully, said he, when thine accusers also are come: and he commanded him to be kept in Herod`s palace." — Acts 23:35 (ASV)

In Herod's judgment hall. Greek, In the praetorium of Herod. The word here used denoted, formerly, the tent of the Roman praetor; and as that was the place where justice was administered, it came to be applied to halls, or courts of justice. This was probably built by Herod the Great as his palace, or as a place for administering justice. It is probable also that prisons, or places of security, would be attached to such places.