Isaiah 30:28
And his breath, as an overflowing stream, shall reach to the midst of the neck, to sift the nations with the sieve of vanity: and there shall be a bridle in the jaws of the people, causing them to err. And his breath, as an overflowing stream, shall reach to the midst of the neck, to sift the nations with the sieve of vanity: and there shall be a bridle in the jaws of the people, causing them to err.
The overflowing stream reaching to the midst of the neck is God sifting the nations in the day of final judgment. That sifting takes place at the final awards, when He separates those who have kept the truth from those who exalt themselves against Him. The fall of Assyria stands as the object lesson of this judgment, warning nations in ancient times and in the present that arrogantly oppose God.
In that sifting those who have kept the truth will be permitted to enter the city of God. Those who exalt themselves against Him, the proud nations, will face destruction.