John Calvin Commentary Acts 19:17

"And this became known to all, both Jews and Greeks, that dwelt at Ephesus; and fear fell upon them all, and the name of the Lord Jesus was magnified." — Acts 19:17 (ASV)

There came fear. The fruit of that vengeance, which God brought upon those who wickedly abused the name of Christ, is this: that they were all moved to reverence, so that they would not despise that doctrine, whose avenger the Lord had shown by a clear sign and testimony He would be, and they were all led to reverence Christ.

For, besides God inviting us by all His judgments to the point where they terrify us from sinning, in this example particularly was the majesty of Christ set forth, and the authority of the gospel established.

Therefore, a heavier and more grievous punishment is prepared for deceivers who knowingly profane the name of Christ with their enchantments, lest they assure themselves that they will escape unpunished for such gross sacrilege.

When it says that this was made known to everyone, it means commonly or everywhere. For the meaning is that the event was widely discussed among the people, so that the name of Christ might be made known to more people.