Ezekiel 21:9–11

Iron sharpens iron. Holy Spirit will take the Word of God and precept by precept changes us into the image of His Son. He corrects those He loves and only in the full armor of the Spirit can we stand against the principles of darkness.

Jeremiah 46:4 Harness the horses, and mount up, you horsemen! Stand forth with your helmets, polish the spears, put on the armor!

Because He is God and we are not, we can lean on the fact He sees and knows all. Because He is holy, we can trust Him. Because He is working out our salvation, we can be sanctified, be more like Christ and live in abundance with Him. Because we can remember what He has already done. Not just in our lives. He is always making a way for us to be with Him. First5 

Ezekiel 21:9–11 

9 “Son of man, prophesy and say, ‘Thus says the Lord!’ Say: ‘A sword, a sword is sharpened And also polished! 10 Sharpened to make a dreadful slaughter, Polished to flash like lightning! Should we then make mirth? It despises the scepter of My son, As it does all wood. 11 And He has given it to be polished, That it may be handled; this sword is sharpened, and it is polished To be given into the hand of the slayer.’ The New King James Version

The sword is made ready for Yahweh’s use in judgment. The connection between the sword and the flash of lightning may be based on a Babylonian literary motif. The Akkadian sign for “sword” and “lightning” are the same. A Babylonian poem also depicts a divine destroyer identified as both “torch” and “sword”. Faithlife Study Bible

The Babylonian army led by Nebuchadnezzar—the sword—is pictured as ready and moving swiftly. While verses 9–17 are written as Hebrew poetry, the lines actually meant to be sung may have been limited to these in verses  9–11. In this context, My son, refers to Judah. If the people reacted with mirth, it would show that they mistakenly believed that such judgment would never come on God’s people and must therefore be meant for an enemy nation. The NKJV Study Bible

Whatever instruments God uses in executing his judgments, he will strengthen them according to the service they are employed in. The sword glitters to the terror of those against whom it is drawn. It is a sword to others, a rod to the people of the Lord. Matthew Henry’s Concise Commentary

Deuteronomy 32:41 if I whet My glittering sword, and My hand takes hold on judgment, I will render vengeance to My enemies, and repay those who hate Me.

Ezekiel 21:15 I have set the point of the sword against all their gates, that the heart may melt and many may stumble. Ah! It is made bright; it is grasped for slaughter: