Praise ye the Lord. Sing ye unto the Lord a new song: let his praise be heard in the Congregation of Saints.
Let ye Saints be joyful with glory: let them sing loud upon their beds. Let the high Acts of God be in their mouth, and a two edged sword in their hands,
Psalms 149:1, 5-6 GNV
Well that way of praise thinking went sideways fast! Oh, the thinking is absolutely correct. It just doesn't fit our typical way of thinking about praise, about the high Acts of God. Praise God with our mouth, and have a two edged sword in their hand? That would liven up some congregations!
This does bring to mind that God said, "Vengeance is mine, I will repay, thus saith the Lord". So how does that work?
In Exodus 14 Moses tells the people"the Lord will fight for you" and the sea collapsed upon the enemy. (They didn't have the means to fight anyway.) After that God's promise in Exodus 23 was that He would send hornets to drive nations out of the land. This was promised again in Deuteronomy 7, and said it was fulfilled in Joshua 24. Later in Joshua 6 we have the Guinness Book of Records candidate for battle plans with major destruction of insurmountable wall defenses after a ten mile hike and everyone yelling and the priests blowing their horns. Again in 2 Samuel 18 in the battle between Absalom and David's men we are told the wood devoured more men than the sword. When Jesus and the disciples left the upper room for the Garden of Gethsemane Jesus told them in Luke 22 that times were different now than when He sent them out two by two. He even illustrated the fact that they should sell a garment and buy a sword. They said, We have two, and He said, it is enough. Peter tried using one later in the garden, but Jesus told him that they that take up the sword will perish by the sword. That was after Jesus had demonstrated moments before that just His words alone could knock down 600 men.
According to this psalm it is a new song to be sung. Even this psalmist saw God's great victories with new songs sung both in Revelation
5 and 14. We may have swords, but the battle and victory will be and is God's and God's alone.