Psalm 149
A new song with dancing and tambourines, because "the LORD takes pleasure in His people" and beautifies the afflicted. The second half, praises in the mouth and a sword in the hand, reflects Israel's holy-war setting; the New Testament turns the sword into the word of God (Ephesians 6:17, Hebrews 4:12). The joy line is the one to hold: God enjoys His people.
"For the LORD takes pleasure in His people; He adorns the afflicted with salvation." (Psalm 149:4)