I will send a fire upon Judah - All know now, how Jerusalem, its temple, and its palaces perished by fire, first by Nebuchadnezzar, then by the Romans. Yet some two centuries passed, before that first destruction came. The ungodly Jews flattered themselves that it would never come. So we know that a "fiery stream" Daniel 7:10 will issue and come forth from Him; "a fire" that "consumeth to destruction" Job 31:12, all who, whether or no they are in the body of the Church, are not of the heavenly Jerusalem; dead members in the body which belongs to the Living Head. And it will not the less come, because it is not regarded. Rather, the very condition of all God's judgments is, to be disregarded and to come, and then most to come, when they are most disregarded.

I will send a fire upon Judah - This fire was the war made upon the Jews by Nebuchadnezzar, which terminated with the sackage and burning of Jerusalem and its palace the temple.

But I will send a fire upon Judah,.... An enemy, Nebuchadnezzar, who should burn, waste, and destroy, all that were in his way:
and it shall devour the palaces of Jerusalem; the chief city of Judah, the royal city, where stood the temple, the palace of the most High, and the palaces of the king and his nobles; these were burnt with fire when it was taken by the Chaldean army, about two hundred years after this prophecy, Jeremiah 52:13.

a fire--Nebuchadnezzar.