Albert Barnes Commentary Acts 16:19

"But when her masters saw that the hope of their gain was gone, they laid hold on Paul and Silas, and dragged them into the marketplace before the rulers," — Acts 16:19 (ASV)

The hope of their gains was gone. This is what troubled and enraged them, and it is as likely to enrage people as anything. Instead of viewing the act as proof of Divine power, they were focused only on their profits.

Their indignation provides a remarkable illustration of the fixedness with which people regard wealth; of the fact that the love of it will blind them to all the truths of religion and all the proofs of God's power and presence; and of the fact that any Divine intervention destroying their hopes of gain fills them with wrath, hatred, and murmuring.

Many a man has been opposed to God and his gospel because, if religion became widespread, his hopes of gain would be gone. Many a slave-dealer, many a seller of strong alcoholic drink, and many a man engaged in other unlawful ways of profiting have been unwilling to abandon their occupations, simply because their hopes of gain would be destroyed. A significant part of the opposition to the gospel arises from the fact that, if embraced, it would strike at many of the dishonorable occupations of men and make them honest and conscientious.

The marketplace. This refers to the court, or forum. The marketplace was a public gathering place, and courts were often held in or near such locations.

The rulers. The term used here commonly refers to civil magistrates.