Genesis 11:7

7Come, alet us go down and there confuse their language, so that they may not understand one another’s speech.”

Genesis 42:23

23They did not know that Joseph understood them, for there was an interpreter between them.

Deuteronomy 28:49

49 bThe Lord will bring a nation against you from far away, from the end of the earth, cswooping down like the eagle, a nation dwhose language you do not understand,

2 Kings 18:26

26Then eEliakim the son of Hilkiah, and fShebnah, and Joah, said to the Rabshakeh, “Please speak to your servants in gAramaic, for we understand it. Do not speak to us in the language of Judah within the hearing of the people who are on the wall.”

Acts 2:4-11

4And they were all hfilled with the Holy Spirit and began ito speak in other tongues jas the Spirit gave them utterance.

5Now there were dwelling in Jerusalem Jews, devout men from every nation under heaven. 6And kat this sound the multitude came together, and they were bewildered, because each one was hearing them speak in his own language. 7And lthey were amazed and astonished, saying, “Are not all these who are speaking mGalileans? 8And how is it that we hear, each of us in his own native language? 9Parthians and nMedes and oElamites and residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia, 10Phrygia and Pamphylia, Egypt and the parts of Libya belonging to Cyrene, and visitors from Rome, 11both Jews and pproselytes, Cretans and Arabians—we hear them telling in our own tongues the mighty works of God.”

Acts 10:46

46For they were hearing them qspeaking in tongues and extolling God. Then Peter declared,

1 Corinthians 14:9-11

9So with yourselves, if with your tongue you utter speech that is not intelligible, how will anyone know what is said? For you will be rspeaking into the air. 10There are doubtless many different languages in the world, and none is without meaning, 11but if I do not know the meaning of the language, I will be sa foreigner to the speaker and the speaker a foreigner to me.

1 Corinthians 14:16

16Otherwise, if you give thanks with your spirit, how can anyone in the position of an outsider
Or  of him that is without gifts
say uAmento vyour thanksgiving when he does not know what you are saying?

1 Corinthians 14:21-22

21 wIn the Law it is written, xBy people of strange tongues and by the lips of foreigners will I speak to this people, and even then they will not listen to me, says the Lord.” 22Thus tongues are a sign not for believers but for unbelievers, while prophecy is a sign
Greek lacks  a sign
not for unbelievers but for believers.
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