Because of a vision in Troas, Paul went to preach in Macedonia.

Acts 16:6-10

6 Paul and his companions wanted/planned to enter Asia province and preach the message about Jesus there, but they were prevented by the Holy Spirit {the Holy Spirit prevented them} from going there. So they traveled through Phrygia and Galatia provinces. 7 They arrived at the border of Mysia province and they wanted to go north into Bithynia province. But again the Spirit of Jesus showed them that they should not go there. 8 So they went through Mysia province and arrived at Troas, a port city. I, Luke, joined them there. 9 That night God gave Paul a vision in which he saw a man who was a native of Macedonia province. He was standing some distance away, and he was earnestly calling to Paul, “Please come over here to Macedonia and help us!” 10 The next morning we (exc) immediately got ready to go to Macedonia, because we believed that God had called us to go and preach the good message to the people there.