Isaiah 33:19

Thou shall not see the fierce people, a people of a deep speech that thou cannot comprehend, of a strange tongue that thou cannot understand.

Isaiah 28:11

No, but by [men of] strange lips and with another tongue he will speak to this people,

Deuteronomy 28:49-50

LORD will bring a nation against thee from far, from the end of the earth, as the eagle flies, a nation whose tongue thou shall not understand,

Jeremiah 5:15

Lo, I will bring a nation upon you from far, O house of Israel, says LORD. It is a mighty nation. It is an ancient nation, a nation whose language thou know not, nor understand what they say.

2 Kings 19:32

Therefore thus says LORD concerning the king of Assyria, He shall not come to this city, nor shoot an arrow there, neither shall he come before it with shield, nor cast up a mound against it.

Ezekiel 3:5-6

For thou are not sent to a people of a strange speech and of a hard language, but to the house of Israel,

Exodus 14:13

And Moses said to the people, Fear ye not. Stand still, and see the salvation of LORD, which he will work for you today, for the Egyptians whom ye have seen today, ye shall see them again no more forever.

1 Corinthians 14:21

In the law it is written, In other tongues and in other lips I will speak to this people, and not even so will they hear me, says Lord.

Treasury of Scripture Knowledge

Summary

Thou shalt not see a fierce people, a people of a deeper speech than thou canst perceive; of a stammering tongue, that thou canst not understand.

Bible References

Shalt not

Exodus 14:13
And Moses said to the people, Fear ye not. Stand still, and see the salvation of LORD, which he will work for you today, for the Egyptians whom ye have seen today, ye shall see them again no more forever.
Deuteronomy 28:49
LORD will bring a nation against thee from far, from the end of the earth, as the eagle flies, a nation whose tongue thou shall not understand,
2 Kings 19:32
Therefore thus says LORD concerning the king of Assyria, He shall not come to this city, nor shoot an arrow there, neither shall he come before it with shield, nor cast up a mound against it.

Deeper

Isaiah 28:11
No, but by [men of] strange lips and with another tongue he will speak to this people,
Jeremiah 5:15
Lo, I will bring a nation upon you from far, O house of Israel, says LORD. It is a mighty nation. It is an ancient nation, a nation whose language thou know not, nor understand what they say.
Ezekiel 3:5
For thou are not sent to a people of a strange speech and of a hard language, but to the house of Israel,
1 Corinthians 14:21
In the law it is written, In other tongues and in other lips I will speak to this people, and not even so will they hear me, says Lord.