Acts 9:15 (ESV)

15 But the Lord said to him, “Go, for he is a chosen instrument of mine to carry my name before the Gentiles and kings and the children of Israel.

Acts 13:1-3 (ESV)

13 Now there were in the church at Antioch prophets and teachers, Barnabas, Simeon who was called Niger, Lucius of Cyrene, Manaen a lifelong friend of Herod the tetrarch, and Saul. 2 While they were worshiping the Lord and fasting, the Holy Spirit said, “Set apart for me Barnabas and Saul for the work to which I have called them.” 3 Then after fasting and praying they laid their hands on them and sent them off.

Acts 14:21-23 (ESV)

21 When they had preached the gospel to that city and had made many disciples, they returned to Lystra and to Iconium and to Antioch, 22 strengthening the souls of the disciples, encouraging them to continue in the faith, and saying that through many tribulations we must enter the kingdom of God. 23 And when they had appointed elders for them in every church, with prayer and fasting they committed them to the Lord in whom they had believed.