Psalm 149 is on praising Jehovah for His pleasure in His people, Israel, and His adornment of the lowly with salvation.
Verse 1 speaks of singing a new song to Jehovah and His praise in the congregation of His saints.
Verse 2 says, "Let Israel rejoice in his Maker;/Let the children of Zion be glad in their King." Verse 3 speaks of praising His name with dancing and of singing psalms to Him with the tambourine and the lyre. Jehovah takes pleasure in His people and adorns the lowly with salvation (v. 4). Thus, verses 5 and 6 say that the faithful ones should exult in glory and give a ringing shout upon their beds, with the high praises of God in their mouth and a two-edged sword in their hand.
Verses 7 through 9a say that the saints should execute vengeance on the nations and punishment among the peoples, bind the kings of the peoples with fetters and their nobles with chains of iron, and execute upon them the judgment written. This honor is for all His faithful ones (v. 9b).