Jamieson, Fausset and Brown on Acts 18:9-11

9-11. Then spake the Lord to Paul ... by a vision, Be not afraid ... no man shall set on thee to hurt thee, &c.--From this it would seem that these signal successes were stirring up the wrath of the unbelieving Jews, and probably the apostle feared being driven by violence, as before, from this scene of such promising labor. He is reassured, however, from above.