Ezekiel 21:5

Modern

Then all flesh will know that I, the LORD, have taken My sword from its sheath, not to return it again.’

Traditional

That all flesh may know that I the Lord have drawn forth my sword out of his sheath: it shall not return any more.

Literal

And all flesh will know that I, YHWH, have drawn My sword from its sheath; it will not return anymore!’

Latin

…ut sciat omnis caro quia ego Dominus, eduxi gladium meum de vagina sua irrevocabilem.

Hebrew

English

Then all flesh will know that I, the LORD, have taken My sword from its sheath, not to return it again.’

The Lord himself was the true enemy Israel needed to fear. He was about to bring a complete judgment against them.
Normally, people expect the righteous to escape judgment and the wicked to receive it. This contrast is like the green tree and the dry tree in the parable (Ezekiel 20:47–48).
God’s judgment on sin would be like a very hot fire. It would burn everything it touched.

This chapter repeatedly mentions a sword (Ezekiel 21:3–5, 9, 11–12, 14–16, 19, 28–30). Each time, the sword represents God’s judgment.

Ezekiel 21:30
Return the sword to its sheath! In the place where you were created, in the land of your origin, I will judge you.
Nahum 1:9
Whatever you plot against the LORD, He will bring to an end. Affliction will not rise up a second time.
Ezekiel 20:48
Then all people will see that I, the LORD, have kindled it; it will not be quenched.”
1 Samuel 3:12
On that day I will carry out against Eli everything I have spoken about his house, from beginning to end.
Jeremiah 23:20
The anger of the LORD will not turn back until He has fully accomplished the purposes of His heart. In the days to come you will understand this clearly.
Numbers 14:21–23
“Yet as surely as I live and as surely as the whole earth is filled with the glory of the LORD,
Isaiah 45:23
By Myself I have sworn; truth has gone out from My mouth, a word that will not be revoked: Every knee will bow before Me, every tongue will swear allegiance.
Deuteronomy 29:24–28
So all the nations will ask, ‘Why has the LORD done such a thing to this land? Why this great outburst of anger?’
1 Kings 9:7–9
…then I will cut off Israel from the land that I have given them, and I will banish from My presence this temple I have sanctified for My Name. Then Israel will become an object of scorn and ridicule among all peoples.
Isaiah 55:11
…so My word that proceeds from My mouth will not return to Me empty, but it will accomplish what I please, and it will prosper where I send it.