Acts 13:5

13:5 When they arrived in Salamis, they began to proclaim the word of God in the Jewish synagogues. (Now they also had John as their assistant.)

Acts 13:13

Paul and Barnabas at Pisidian Antioch

13:13 Then Paul and his companions put out to sea from Paphos and came to Perga in Pamphylia, but John left them and returned to Jerusalem.

Acts 15:37

15:37 Barnabas wanted to bring John called Mark along with them too,