Thou shaft not see a fierce people. The word nvz (nognaz) is translated by some "strong," and by others "impudent;" but, undoubtedly, he intends to express the fierceness of the Assyrians, which he afterwards affirms by saying that they would have no intercourse with them, because they spoke a different language. Nothing is more fitted to excite men to compassion than the intercourse of speech, by which men explain their distresses to each other. When this is wanting, there can be no means of gaining 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, dwells largely on the wretched condition of the people, in order to shew, on the other hand, how great was the kindness of God in delivering them from so great terror. In like manner, the Holy Spirit magnifies the grace of God, in preserving his people in Egypt, though "they did not understand the language of that nation." (Psalm 131:5.)

Thou shalt not see a fierce people - Or, rather, 'this fierce and boasting people you shall not see.' They shall not enter the city; but though they are advancing with so much confidence, they shall be suddenly cut, off and destroyed. The word rendered "fierce," (נועז nô‛âz from נעז yâ‛az), probably means strong, or wicked. Lowth renders it, 'barbarous people,' as if it were לועז lô‛ēz. Michaelis also adopts this reading by supposing an error in transcribing, a change of the Hebrew letter נ (n) into the Hebrew letter ל (l). Such a change might have easily occurred, but there is no authority from the manuscripts for making an alteration in the text The word strong, or mighty, agrees well with the connection.
A people of a deeper speech - A people whose language is so deep, that is, so dark, or obscure, that it cannot be understood by you. This refers to the army of the Assyrians, who spoke the Syrian language, which was understood by some of the Jews, but which was unintelligible to the mass (see Isaiah 36:11).
Than thou canst perceive - Than you can understand.
Of a stammering tongue - (see the note at Isaiah 28:11). Margin, 'Ridiculous;' a sense which the Hebrew will bear, but the more appropriate meaning is that of a barbarous, or unintelligible foreign language.

Thou shalt not see a fierce people,.... A people of a fierce countenance, as in Daniel 8:23 fierce in their looks, furious in their temper, cruel and bloodthirsty in their practices, confirmed and hardened in their sins, whose consciences are seared as with a red hot iron; a character given of the Papists, 1-Timothy 4:2 these shall be no more seen nor feared:
a people of a deeper speech than thou canst perceive; than the people in common could, having their worship and devotion not in their mother tongue, but in the Latin tongue:
of a stammering tongue, that thou canst not understand: meaning the same as before, a barbarous language, as everyone is to those who understand it not; so the Syriac and Assyrian languages were to the Jews, 2-Kings 18:26 and so the Roman language to other nations; but now no more to be used in religious worship; nor shall the church of God be any more visited by Turks or Papists, and be in any dread of them more.

fierce people--The Assyrians shall not be allowed to enter Jerusalem (2-Kings 19:32). Or, thou shalt not any longer see fierce enemies threatening thee as previously; such as the Assyrians, Romans, and the last Antichristian host that is yet to assail Jerusalem (Deuteronomy 28:49-50; Jeremiah 5:15; Zac 14:2).
stammering--barbarous; so "deeper," &c., that is, unintelligible. The Assyrian tongue differed only in dialect from the Hebrew, but in the Assyrian levies were many of non-Semitic race and language, as the Medes, Elamites, &c. (see on Isaiah 28:11).

A fierce - That fierce and warlike people, whom thou hast seen with terror, near the walls of Jerusalem, thou shalt see no more. A people - A foreign nation, whose language is unknown to thee.