1 Corinthians 14:2

For he that speaketh in an [unknown] tongue speaketh not to men, but to God; for no one heareth; but in the Spirit he speaketh mysteries;

1 Corinthians 13:2

And though I have the gift of prophecy, and understand all mysteries and all knowledge, and though I have all faith, so as to remove mountains, and have not love, I am nothing.

Mark 16:17

And these signs will accompany believers: In my name they will cast out demons; they will speak with new tongues;

Acts 10:46

for they heard them speaking with tongues, and magnifying God. Then answered Peter,

Acts 19:6

And when Paul bad laid his hands on them, the Holy Spirit came upon them, and they spoke with tongues, and prophesied.

Matthew 13:11

He answered and said, Because to you it hath been given to know the mysteries of the kingdom of heaven; but to them it hath not been given.

Mark 4:11

And he said to them, To you hath been given the mystery of the kingdom of God; but to them, who are without, all things are done in parables; t

Acts 2:4-11

And they were all filled with the Holy Spirit, and began to speak with other tongues, even as the Spirit gave them utterance.

Acts 22:9

And they that were with me saw indeed the light, and were afraid; but the voice of him that spoke to me they did not hear.

Romans 16:25

Now to him who is able to establish you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery which for eternal ages was unrevealed,

1 Corinthians 2:7

but we speak Gods wisdom in a mystery, the hidden wisdom, which God determined on before the world was, for our glory;

1 Corinthians 2:10

For God hath revealed them to us by his Spirit; for the Spirit searcheth all things, even the depths of God.

1 Corinthians 14:9-11

So also ye, unless ye utter by the tongue words easy to be understood, how shall that be known which is spoken? For ye will be speaking into the air.

1 Corinthians 14:16

Else, if thou bless with the spirit, how shall he that occupieth the place of the unlearned say the Amen at thy giving of thanks, since he understandeth not what thou art saying?

1 Corinthians 14:18-23

I thank God, I speak in an [unknown] tongue more than ye all;

1 Corinthians 14:27-28

If any one speak in an [unknown] tongue, let it be by two, or, at the most, by three, and in turn; and let one interpret.

1 Corinthians 15:51

Behold, I tell you a mystery. We shall not all sleep; but we shall all be changed,

Ephesians 3:3-9

that by revelation the mystery was made known to me, as I wrote before in few words,

Ephesians 6:19

and for me, that utterance may be given me in the opening of my mouth, to make known with boldness the mystery of the gospel,

Colossians 1:26-27

the mystery which hath been hidden for ages and generations, but hath been now revealed to his saints;

Colossians 2:2

that their hearts may be encouraged, they being knit together in love, and that they may attain to all the riches of a full assurance of the understanding, to the full knowledge of the mystery of God;

1 Timothy 3:9

holding the mystery of the faith in a pure conscience.

1 Timothy 3:16

And confessedly great is the mystery of godliness, in him who was manifested in the flesh, justified in the Spirit, seen by angels, preached among the gentiles, believed on in the world, received up in glory.

Revelation 10:7

but in the days of the voice of the seventh angel, when he is about to sound, then should be finished the mystery of God, as he declared the glad tidings to his servants the prophets.

Treasury of Scripture Knowledge

Summary

For he that speaketh in an unknown tongue speaketh not unto men, but unto God: for no man understandeth him; howbeit in the spirit he speaketh mysteries.

Understandeth

Bible References

He that

1 Corinthians 14:9
So also ye, unless ye utter by the tongue words easy to be understood, how shall that be known which is spoken? For ye will be speaking into the air.
Acts 2:4
And they were all filled with the Holy Spirit, and began to speak with other tongues, even as the Spirit gave them utterance.
Acts 10:46
for they heard them speaking with tongues, and magnifying God. Then answered Peter,
Acts 19:6
And when Paul bad laid his hands on them, the Holy Spirit came upon them, and they spoke with tongues, and prophesied.

Understandeth

Acts 22:9
And they that were with me saw indeed the light, and were afraid; but the voice of him that spoke to me they did not hear.

Howbeit

1 Corinthians 2:7
but we speak Gods wisdom in a mystery, the hidden wisdom, which God determined on before the world was, for our glory;
1 Corinthians 13:2
And though I have the gift of prophecy, and understand all mysteries and all knowledge, and though I have all faith, so as to remove mountains, and have not love, I am nothing.
1 Corinthians 15:51
Behold, I tell you a mystery. We shall not all sleep; but we shall all be changed,
Matthew 13:11
He answered and said, Because to you it hath been given to know the mysteries of the kingdom of heaven; but to them it hath not been given.
Mark 4:11
And he said to them, To you hath been given the mystery of the kingdom of God; but to them, who are without, all things are done in parables; t
Romans 16:25
Now to him who is able to establish you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery which for eternal ages was unrevealed,
Ephesians 3:3
that by revelation the mystery was made known to me, as I wrote before in few words,
Ephesians 6:19
and for me, that utterance may be given me in the opening of my mouth, to make known with boldness the mystery of the gospel,
Colossians 1:26
the mystery which hath been hidden for ages and generations, but hath been now revealed to his saints;
Colossians 2:2
that their hearts may be encouraged, they being knit together in love, and that they may attain to all the riches of a full assurance of the understanding, to the full knowledge of the mystery of God;
1 Timothy 3:9
holding the mystery of the faith in a pure conscience.
Revelation 10:7
but in the days of the voice of the seventh angel, when he is about to sound, then should be finished the mystery of God, as he declared the glad tidings to his servants the prophets.