Romans 15:20

In this way I have aspired to preach the gospel where Christ was not known, so that I would not be building on someone else’s foundation.
BSB · Berean Standard Bible
Yea, so have I strived to preach the gospel, not where Christ was named, lest I should build upon another man’s foundation:
KJV · King James Version
yes, making it my aim to preach the Good News, not where Christ was already named, that I might not build on another’s foundation.
WEB · World English Bible
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;
ASV · American Standard Version

Related passages

From the Treasury of Scripture Knowledge, grouped by the word they explain.

so
2 Corinthians 10:14–16
build
1 Corinthians 3:9–15; 2 Corinthians 10:13–16; Ephesians 2:20–22