1 Corinthians
King James Version (KJV)

“According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon.”
King James Version (KJV)
3:10 According to the grace of God given to me - This he premises, lest he should seem to ascribe it to himself. Let every one take heed how he buildeth thereon - That all his doctrines may be consistent with the foundation.
1Co 3:10 According to the grace of God which is given to me. Given when? When he was called to be an apostle. I have laid the foundation. The figure of the building is retained. Paul is a discreet master-builder. He had laid the foundation at Corinth, when he was preaching Christ, and working through faith in him (1Co 2:4,5). Notice it is not "a foundation", but "the foundation", because God's spiritual temple can have only one (1Co 3:16). Another buildeth thereon. After Paul left Corinth, Apollos and other teachers continued to build upon the foundation that Paul had laid. Let every man take heed how he buildeth thereupon. Since there is only one foundation of the temple, viz.: Jesus Christ, there should be most careful and conscientious building upon it (1Co 3:12).