Charles Ellicott Commentary Romans 15:20

"yea, making it my aim so to preach the gospel, not where Christ was [already] named, that I might not build upon another man`s foundation;" — Romans 15:20 (ASV)

Yea, so have I strived.—Rather, but making it my ambition. The Apostle set it before him as a point of honour, not merely to carry forward a work that others had begun, but to build up the whole edifice from the foundation himself.

Not where Christ was named.—Not in places where there were Christians already.

Another man’s foundation.—Compare 2 Corinthians 10:15–16; and for the use of the word “foundation” for the first preaching of the gospel, 1 Corinthians 3:10.

On verses 20, 21:

Throughout all this long missionary career, the Apostle had made it his endeavour not merely to go over old ground where others had been before him, but to seek out new and virgin soil, where he might enter as a pioneer, and convey the good news of the kingdom of heaven for the first time.