1Corinthians 14:9-19 So likewise you, except you utter by the tongue words easy to be understood, how shall it be known what is spoken? for you shall speak into the air. There are, it may be, so many kinds of voices in the world, and none of them is without signification. Therefore if I know not the meaning of the voice, I shall be unto him that speaks a barbarian, and he that speaks shall be a barbarian unto me. Even so you, forasmuch as you are zealous of spiritual gifts, seek that you may excel to the edifying of the church. Wherefore let him that speaks in an unknown tongue pray that he may interpret. For if I pray in an unknown tongue, my spirit prays, but my understanding is unfruitful. What is it then? I will pray with the spirit, and I will pray with the understanding also: I will sing with the spirit, and I will sing with the understanding also. Else when thou shall bless with the spirit, how shall he that occupies the room of the unlearned say Amen at thy giving of thanks, seeing he understands not what thou say? For thou verily give thanks well, but the other is not edified.
‘Easy to be understood’ [Greek: eusemos] intelligible.
‘Kinds of voices’ – kinds of languages. All of them are intelligible to those who speak them.
‘Let him that speaks in an unknown tongue pray that he may interpret’ – a command to those who speak in tongues.
‘For if I pray in an unknown tongue, my spirit prays, but my understanding is unfruitful.’ This is Paul’s reason for praying for the interpretation. The understanding is unfruitful unless the tongues are interpreted. Edification of a broken spirit take place when an individual speaks in an unknown language – God can then speak words of healing and restoration without our interference.
‘I will pray with the spirit, and I will pray with the understanding also’ – I will pray in tongues or by the Spirit (as in 1Corinthians 14:14) and I will pray with the interpretation of my prayer also (14:14-16).
‘Else when thou shall bless with the spirit, how shall he that occupies the room of the unlearned say Amen at thy giving of thanks, seeing he understands not what thou say?’ When you say the blessing in tongues or in the Spirit, how can it be understood? You give thanks in tongues well, but your host is not edified. He does not know whether you curse or bless the food. You must learn to use your gifts rightly and in the proper place.