Isaiah 66:16 KJV

For by fire and by his sword will the LORD plead with all flesh: and the slain of the LORD shall be many.

Every enemy of the church shall be destroyed, and the final ruin of ungodly men shall be seenA prophetic declaration is given of the Lord's vengeance on all enemies of his church, especially that of all antichristian opposers of the gospel in the...

Isaiah 27:1 In that day the LORD with his sore and great and strong sword shall punish leviathan the piercing serpent, even leviathan that crooked serpent; and he shall slay the dragon that is in the sea.
Ezekiel 38:21–22 And I will call for a sword against him throughout all my mountains, saith the Lord GOD: every man's sword shall be against his brother. …
Isaiah 30:30 And the LORD shall cause his glorious voice to be heard, and shall shew the lighting down of his arm, with the indignation of his anger, and with the flame of a devouring fire, with scattering, and tempest, and hailstones.
Isaiah 34:5–10 For my sword shall be bathed in heaven: behold, it shall come down upon Idumea, and upon the people of my curse, to judgment. …
Ezekiel 39:2–10 And I will turn thee back, and leave but the sixth part of thee, and will cause thee to come up from the north parts, and will bring thee upon the mountains of Israel: …
Revelation 19:11–21 And I saw heaven opened, and behold a white horse; and he that sat upon him was called Faithful and True, and in righteousness he doth judge and make war. …

From OpenBible.info, most relevant first.

Church Prophecies concerning prosperity of Church
Gentiles Prophecies of the conversion of Gentiles
Israel, prophecies concerning Of blessing and restoration
Jesus, the Christ Prophecies concerning universality of the kingdom of Jesus, the Christ

Timeline of the Bible808–698 BC · Isaiah, in the days of Uzziah, Jotham, Ahaz, and Hezekiah

For by fire כִּי kî Conjunction בָאֵשׁ bāʾēš אֵשׁ Noun · masculine or feminine singular · with preposition with the
and by his sword וּבְחַרְבּוֹ ûbĕḥarbô חֶרֶב Noun · feminine singular construct · with and, preposition, suffix: third person masculine singular
will the LORD יְהוָה yhwh יְהֹוָה Proper name
plead נִשְׁפָּט nišpāṭ שָׁפַט Verb · niphal active participle, masculine singular
with all flesh אֶת ʾet Preposition כָּל kol Noun · masculine singular construct בָּשָׂר bāśār בָּשָׂר Noun · masculine singular
and the slain חַלְלֵי ḥallê חָלָל Adjective · masculine plural construct
of the LORD יְהוָה yhwh יְהֹוָה Proper name
shall be many וְרַבּוּ wĕrabbû רָבַב Verb · qal sequential perfect, third person common plural · with and

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