1 Corinthians 16:5

At the time he wrote, Paul planned to head north from Ephesus and then east and to spend some time in Macedonia. Macedonia was the Roman province north of Corinth where Philippi, Thessalonica, and Berea stood. He then planned to travel south to Corinth. Paul later changed this plan and traveled directly from Ephesus to Corinth (2 Corinthians 2:1; 2 Corinthians 12:14; 2 Corinthians 13:1-2) and returned to Ephesus (cf. 2 Corinthians 2:5-8; 2 Corinthians 7:12). Later he visited Macedonia and then Corinth (2 Corinthians 2:12-13; 2 Corinthians 7:6-16). [Note: See Richard Batey, "Paul’s Interaction with the Corinthians," Journal of Biblical Literature 84 (1985):139-43.]