1 Corinthians 1:17,19,21
For Christ sent me not to baptize, but to preach the gospel: not with wisdom of words, lest the cross of Christ should be made of none effect.
Nave's Topical Index—AKJV

1 Corinthians 2:1-5,13
And I, brothers, when I came to you, came not with excellency of speech or of wisdom, declaring to you the testimony of God.
Nave's Topical Index—AKJV