13 Wherefore let him that speaks with a tongue pray that he may interpret.
14 For if I pray with a tongue, my spirit prays, but my understanding is unfruitful.
15 What is it then? I will pray with the spirit, but I will pray also with the understanding; I will sing with the spirit, but I will sing also with the understanding.
16 Since otherwise, if thou blessest with the spirit, how shall he who fills the place of the simple Christian say Amen, at thy giving of thanks, since he does not know what thou sayest?
17 For thou indeed givest thanks well, but the other is not edified.
18 I thank God I speak in a tongue more than all of you:
19 but in the assembly I desire to speak five words with my understanding, that I may instruct others also, rather than ten thousand words in a tongue.