{Special miracles} (dunameis ou tas tuchousas). "Powers
not the ones that happen by chance," "not the ordinary ones,"
litotes for "the extraordinary." All "miracles" or "powers"
(dunameis) are supernatural and out of the ordinary, but here
God regularly wrought (epoiei), imperfect active) wonders
beyond those familiar to the disciples and completely different
from the deeds of the Jewish exorcists. This phrase is peculiar
to Luke in the N.T. (also  28:2 ), but it occurs in the classical
Greek and in the _Koin(825f) as in III Macc. 3:7 and in papyri and
inscriptions (Deissmann, _Bible Studies_, p. 255). In Samaria
Philip wrought miracles to deliver the people from the influence
of Simon Magus. Here in Ephesus exorcists and other magicians had
built an enormous vogue of a false spiritualism and Paul faces
unseen forces of evil. His tremendous success led some people to
superstitious practices thinking that there was power in Paul's
person.