John Calvin Commentary Isaiah 33:19

"Thou shalt not see the fierce people, a people of a deep speech that thou canst not comprehend, of a strange tongue that thou canst not understand." — Isaiah 33:19 (ASV)

Thou shalt not see a fierce people. The word נועז (nognaz) is translated by some as “strong,” and by others as “impudent”; but, undoubtedly, he intends to express the fierceness of the Assyrians. He later affirms this by stating that they would have no communication with them, because they spoke a different language.

Nothing is more suited to arouse compassion in people than communication through speech, by which people explain their distresses to each other. When this is lacking, there can be no means of reaching their hearts; each party is a barbarian to the other, and nothing more can be obtained from them than if one were dealing with wild and savage beasts.

The Prophet, therefore, elaborates extensively on the wretched condition of the people, in order to show, on the other hand, how great God's kindness was in delivering them from such great terror.

Likewise, the Holy Spirit magnifies the grace of God in preserving His people in Egypt, though they did not understand the language of that nation (Psalms 131:5).