Charles Ellicott Commentary Acts 19:38

"If therefore Demetrius, and the craftsmen that are with him, have a matter against any man, the courts are open, and there are proconsuls: let them accuse one another." — Acts 19:38 (ASV)

The law is open.—Literally, the court, or forum, days are going on. These words may either indicate that the proconsul was then actually sitting to hold trials in the agora or forum, or they may be understood as a colloquial idiom for “there are court days coming.”

There are deputies.—The Greek word is (as in Acts 13:7 and Acts 18:12) the equivalent for proconsul. Strictly speaking, there was only one proconsul in each province, and we must therefore assume either that the expression here is colloquial, that the assessors (consiliarii) of the proconsul were popularly described this way, or that some peculiar combination of circumstances had led to two persons at this time in Ephesus being vested with proconsular authority. There are some grounds for adopting this last alternative. Junius Silanus, who was Proconsul of Asia when St. Paul arrived in Ephesus (AD 54), had been poisoned by Celer and Helius, the two procurators, at the instigation of Agrippina; and it seems probable that they, for a time, held joint proconsular authority.

Let them take legal action against one another.—The specific English term the author likely had in mind, implead, exactly expresses the technical force of the Greek. Demetrius and his followers were to lodge a formal statement of the charge they brought against the accused. They, in turn, were to submit a rejoinder, and so, by joining issue, each side would produce its witnesses.