Romans 15:20

In all this it has been my ambition to preach the good news only where Christ's name was unknown, so as not to build on foundations other men had laid.

2 Corinthians 10:13-16

But my boasting will not be extravagant, nor exceed the limits God has allowed me, which reach all the way to you.

1 Corinthians 3:9-15

For we are fellow-laborers for God, and you are God's farm, God's building.

Ephesians 2:20-22

You are built upon the apostles and prophets as your foundation, and Christ Jesus himself is the cornerstone.

Treasury of Scripture Knowledge

Summary

Yea, so have I strived to preach the gospel, not where Christ was named, lest I should build upon another man's foundation:

Bible References

So

2 Corinthians 10:14
It is no strain for me to do this, as it might be for people who had never got so far, for I was the first to come all the way to you with the good news of the Christ.

Build

1 Corinthians 3:9
For we are fellow-laborers for God, and you are God's farm, God's building.
2 Corinthians 10:13
But my boasting will not be extravagant, nor exceed the limits God has allowed me, which reach all the way to you.
Ephesians 2:20
You are built upon the apostles and prophets as your foundation, and Christ Jesus himself is the cornerstone.