Isaiah 33:19
You shall not see a fierce people, a people of a deeper speech than you can understand; of a foreign tongue that no one understands.
Isaiah 28:11
for with stammering lips and another tongue He will speak to this people.
Deuteronomy 28:49-50
Jehovah shall bring a nation against you from far, from the end of the earth, as the eagle flies; a nation whose tongue you shall not understand,
Jeremiah 5:15
Lo, I will bring a nation on you from afar, O house of Israel, says Jehovah. It is an enduring nation, it is an ancient nation, a nation whose language you do not know, nor understand what they say.
2 Kings 19:32
So Jehovah says this concerning the king of Assyria. He shall not come into this city, nor shoot an arrow there, nor come before it with shield, nor throw up a bank against it.
Ezekiel 3:5-6
For you are not sent to a people of a deep lip and of a difficult language, but to the house of Israel;
Exodus 14:13
And Moses said to the people, Do not fear. Stand still and see the salvation of Jehovah, which He will prepare for you this day. For the Egyptians whom you have seen today, you shall never see them anymore.
1 Corinthians 14:21
In the Law it is written, "By other tongues and other lips I will speak to this people, and even so they will not hear Me, says the Lord."