Jamieson, Fausset and Brown on Acts 13:13

Ac 13:13-52. At Perga John Mark Forsakes Them--At Antioch in Pisidia, Paul Preaches with Glorious Effect--The Jews, Enraged, Expel Them Out of Them Coasts.

13. they came to Perga in Pamphylia--The distance from Paphos to Attalia, on the Gulf of Pamphylia (see on Ac 14:25), sailing in a northwest direction, is not much greater than from Seleucia to Salamis on the east. Perga was the metropolis of Pamphylia, on the river Cestrus, and about seven miles inland from Attalia.

and John departing from them returned to Jerusalem--As Paul afterwards peremptorily refused to take Mark with him on his second missionary journey, because he "had departed [or 'fallen off'] from them and had not gone with them to the work" (Ac 15:38), there can be no doubt that he had either wearied of it or been deterred by the prospect of the dangers which lay before him. (But see on Ac 15:37, &c.).