Isaiah 33:19
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. 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.
Isaiah 33 stands among varied prophecies concerning Israel, with Israel serving as a type of conditions in the Christian age. That portion of Isaiah looks especially ahead to the last days and to God's judgments upon the earth.
Within that setting the verse belongs to the picture and promise of the Lord's coming, amid the last trials and tribulation of God's people and the Lord's judgment. It is part of the word about when the Lord shall come, when Jehovah arises to lift Himself up on high and be exalted. Because its descriptions of the Lord coming to judgment and defending Jerusalem are connected with millennial times, they are to be read as figurative rather than as a literal account of the final coming.
The verse promises a future time when God's people will no longer see or encounter a fierce people of incomprehensible speech. That is the time when the Israel of God will have a pure language. In the great tribulation of the last days human plans and offices perish and hearts are terrified by unexpected events, while God's enemies speak scoffing, fierce words in speech that cannot be understood. Those enemies shall soon perish, whereas the coming King brings gentle words and heavenly comfort to His waiting people. The verse connects with the final scene when the city of God stands on earth and the wicked surround it, and the wicked see the reward of the righteous and recognize that God has spoken truthfully.