Yea, so have I strived to preach the gospel, not where Christ was named, lest I should build upon another man's foundation:
All Commentaries on Romans 15:20 Go To Romans 15
Ambrosiaster
AD 400
It was not without reason that Paul says that he tried to preach in places where Christ had not been named. For he knew that false apostles went about sharing Christ in ways which were wrong in order to ensnare the people by some other teaching under the name of Christ, which was then very difficult to put right afterward. Therefore he wanted to get there first, in order to preach the right message. Commentary on Paul’s Epistles.