Charles Ellicott Commentary Acts 25:21

"But when Paul had appealed to be kept for the decision of the emperor, I commanded him to be kept till I should send him to Caesar." — Acts 25:21 (ASV)

To the hearing of Augustus.—The title is the Greek equivalent, as seen in the name Sebaste (= Augusta) given to Samaria, for the epithet that, like our “his majesty,” had become a kind of official title of the Roman emperor. It had first been given by the Senate to Octavianus (Sueton. Aug. c. 7) and was adopted by his successors. As connected with “augur,” it had originally, like Sebastos, a religious connotation. The month of August, dedicated to the first emperor as July had been dedicated to Julius, and the names of Augsburg and Sebastopol, are interesting as perpetuating its memory.

The word for “hearing” (the same as our medical term diagnosis) corresponds more to our thorough investigation.