John Gill Commentary Acts 19:11

"And God wrought special miracles by the hands of Paul:" — Acts 19:11 (ASV)

And God worked special miracles by the hands of Paul. ] For the confirmation of the doctrine which he preached, and of his mission, as an apostle; and these were not any sort of miracles, common and vulgar ones, and much less things of chance, and what were merely accidental, as the word may signify; but they were rare and uncommon ones, and in which there was a visible display of the power of God; to whom as the efficient cause they are ascribed, the apostle being only an instrument God made use of.