1 Corinthians 14:14

For if I pray in a tongue, my spirit prays but my mind is unproductive.

1 Corinthians 14:2

For the one who speaks in a tongue does not speak to people but to God, because no one understands, but by the Spirit he speaks mysteries.

1 Corinthians 14:15-16

{Therefore what should I do}? I will pray with my spirit, but I will also pray with my mind. I will sing praise with my spirit, but I will also sing praise with my mind.

1 Corinthians 14:19

but in the church I prefer to speak five words with my mind, in order that I may instruct other [people], than ten thousand words in a tongue.

Treasury of Scripture Knowledge

Summary

For if I pray in an unknown tongue, my spirit prayeth, but my understanding is unfruitful.

My spirit

Bible References

My spirit

1 Corinthians 14:2
For the one who speaks in a tongue does not speak to people but to God, because no one understands, but by the Spirit he speaks mysteries.