Jamieson, Fausset and Brown on Acts 16:19

19. when her masters saw that the hope of their gains was gone, they caught Paul and Silas--as the leading persons.

and drew them into the market-place--or Forum, where the courts were.

to the magistrates, saying, &c.--We have here a full and independent confirmation of the reality of this supernatural cure, since on any other supposition such conduct would be senseless.