Translations
So they stayed a long time, speaking boldly for the Lord, who confirmed the message of His grace by enabling signs and wonders to be performed through their hands.
So they stayed there a considerable time, speaking openly and boldly for the Lord, who testified to the word of His covenant-grace by granting signs and wonders to be done through their hands.
Long time therefore abode they speaking boldly in the Lord, which gave testimony unto the word of his grace, and granted signs and wonders to be done by their hands.
So Paul and Barnabas spent considerable time there, speaking boldly for the Lord, who affirmed the message of His grace by enabling them to perform signs and wonders.

