So he sent into Macedonia two of them that ministered unto him, Timotheus and Erastus; but he himself stayed in Asia for a season.
So he sent into Macedonia two of them that ministered unto him, Timotheus and Erastus - as his pioneers, in order (as he tells the Corinthians) to "bring them in remembrance of his ways which were in Christ" (1 Corinthians 4:17), or, in other words, to communicate his mind to them on various matters. (Compare also 1 Corinthians 16:10.) After a brief stay, he wished Timothy to return to him (1 Corinthians 16:11). That this Erastus was the same who is called (in Romans 16:23) "the chamberlain of the city" (of Corinth) is very doubtful. He is again mentioned in 2 Timothy 4:20.
But he himself stayed in (Roman) Asia for a season - meaning, in the province (in contrast with "Macedonia," in the previous clause), and at Ephesus, its capital city.