To preach the gospel in the regions beyond you, and not to boast in another man's line of things made ready to our hand. To preach the Gospel in the regions beyond you - He probably refers to those parts of the Morea, such as Sparta, etc., that lay southward of them; and to Italy, which lay on the west; for it does not appear that he considered his measure or province to extend to Libya, or any part of Africa. See the Introduction, Section 12.
Not to boast in another man's line - So very scrupulous was the apostle not to build on another man's foundation, that he would not even go to those places where other apostles were labouring. He appears to think that every apostle had a particular district or province of the heathen world allotted to him, and which God commissioned him to convert to the Christian faith. No doubt every apostle was influenced in the same way; and this was a wise order of God; for by these means the Gospel was more quickly spread through the heathen provinces than it otherwise would have been. The apostles had deacons or ministers with them whose business it was to water the seed sown; but the apostles alone, under Christ, sowed and planted.