A.T. Robertson Commentary Acts 19:20

"So mightily grew the word of the Lord and prevailed." — Acts 19:20 (ASV)

Mightily (κατα κρατος). According to strength. Only here in N.T., common military term in Thucydides. Such proof of a change counted.

Grew and prevailed (ηυξανεν κα ισχυεν). Imperfect actives, kept growing and gaining strength. It was a day of triumph for Christ in Ephesus, this city of vast wealth and superstition. Ephesus for centuries will be one of the centres of Christian power. Timothy will come here and John the Apostle and Polycarp and Irenaeus.