John Calvin Commentary Acts 16:10

"And when he had seen the vision, straightway we sought to go forth into Macedonia, concluding that God had called us to preach the gospel to them." — Acts 16:10 (ASV)

Being fully persuaded. From this we gather that it was not a mere vision, but that it was also confirmed by the testimony of the Spirit. For Satan often abuses apparitions and illusions to deceive with them, so that he may mock and deceive unbelievers. As a result, a mere vision leaves a person's mind in doubt. But those visions that are truly divine, the Spirit seals with a distinct mark, so that those whom the Lord wants to be certainly devoted to Him may not doubt or waver.

A wicked spirit appeared to Brutus, inviting him to enter that ill-fated combat and battle that he fought at Philippi, even in the very same place to which Paul was later called. But as the cause was very different, so the Lord dealt very differently with His servant, so that He removed his doubt and did not leave him overcome by fear.

Now, in Paul and his companions, the desire to obey immediately followed the certainty; for, as soon as they understood that the Lord called them, they prepared for their journey. The ending of the participle used here is active; and although it has several meanings, I do not doubt that Luke’s meaning is that Paul and the rest, after they had compared this vision with previous divine messages, were fully persuaded that the Lord had called them into Macedonia.