Isaiah 33:19

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

Isaiah 28:11

For with stammering lips and another tongue will he speak to this people.

Deuteronomy 28:49-50

The LORD shall bring a nation against thee from far, from the end of the earth, as swift as the eagle flieth, a nation whose language thou shalt not understand:

Jeremiah 5:15

Lo, I will bring a nation upon you from far, O house of Israel, saith the LORD: it is a mighty nation, it is an ancient nation, a nation whose language thou knowest not, neither understandest what they say.

2 Kings 19:32

Therefore thus saith the LORD concerning the king of Assyria, He shall not come into this city, nor shoot an arrow there, nor come before it with shield, nor cast a bank against it.

Ezekiel 3:5-6

For thou art 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 the LORD, which he will show to you to-day: for the Egyptians whom ye have seen to-day, ye shall see them again no more for ever.

1 Corinthians 14:21

In the law it is written, With men of other tongues and other lips will I speak to this people; and yet for all that will they not hear me, saith the 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 the LORD, which he will show to you to-day: for the Egyptians whom ye have seen to-day, ye shall see them again no more for ever.
Deuteronomy 28:49
The LORD shall bring a nation against thee from far, from the end of the earth, as swift as the eagle flieth, a nation whose language thou shalt not understand:
2 Kings 19:32
Therefore thus saith the LORD concerning the king of Assyria, He shall not come into this city, nor shoot an arrow there, nor come before it with shield, nor cast a bank against it.

Deeper

Isaiah 28:11
For with stammering lips and another tongue will he speak to this people.
Jeremiah 5:15
Lo, I will bring a nation upon you from far, O house of Israel, saith the LORD: it is a mighty nation, it is an ancient nation, a nation whose language thou knowest not, neither understandest what they say.
Ezekiel 3:5
For thou art 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, With men of other tongues and other lips will I speak to this people; and yet for all that will they not hear me, saith the Lord.