In the beginning of the gospel— That is, when he first preached the gospel among the Philippians. See ch. Philippians 1:5. The next verse shows, that the clause, when I departed, &c. should be rendered, when I was departing? &c. Thessalonica was itself in Macedonia, and therefore he had not departed from Macedonia, when they sent to him in Thessalonica; but he was then about to leave that country, to preach the gospel elsewhere, and so needed assistance in order to it.
Related Commentaries of Philippians 4:15
Philippians 4:15
15 Now ye Philippians know also, that in the beginning of the gospel, when I departed from Macedonia, no church communicated with me as concerning giving and receiving, but ye only.