Charles Ellicott Commentary 1 Corinthians 14:18-19

"I thank God, I speak with tongues more than you all: howbeit in the church I had rather speak five words with my understanding, that I might instruct others also, than ten thousand words in a tongue." — 1 Corinthians 14:18-19 (ASV)

I thank my God.—Here the Apostle resumes in the first person, coming back, after the parenthesis, to the continuation of his own desire and example.

He does not undervalue that gift whose misuse and exaggeration he is censuring; he possesses it himself to a remarkable degree.

Yet in the Church (i.e., in any assembly of Christians for prayer or instruction), he would prefer to speak five words with his mind rather than ten thousand with a tongue only. For the object of such assemblies is not private prayer or private ecstatic communion with God, but the edification of others.

The word used for “teach” in this verse is literally our word catechise.