Psalm 99 forms an interesting overlapping set of chaistic structures:
1A: Psa 99:1-3, The LORD is great + highly exalted + let them praise Him + He is holy;
CENTRAL AXIS: Psa 99:4, “The King’s strength also loves justice; You have established equity; You have executed justice and righteousness in Jacob;”
2A: Psa 99:5, Exalt the LORD + worship at His footstool + He is holy.
1A: Psa 99:5, Exalt the LORD our God + worship at His footstool + He is holy;
1B: Psa 99:6-7a, The LORD answered Moses, Aaron, Samuel when they called upon Him;
CENTRAL AXIS: Psa 99:7b, “They kept His testimonies and the ordinance He gave them.”
2B: Psa 99:8, The LORD answered them;
2A: Psa 99:9, Exalt the LORD our God + worship at His footstool + He is holy.
Notice that the opening and closing elements of each structure is the same: The LORD is exalted / exalt the LORD our God + praise Him / worship Him + He is holy. The central axis’ are also paired in this way: the first one extols the King’s (a reference to Messiah) justice, equity and righteousness which He has established. The second one tells that they kept His testimonies and ordinances that He gave them. In fact, the LORD’s justice, equity, and righteousness is revealed and explained in His testimonies and ordinances that He gave Jacob through Moses and Aaron. He is King and executes His justice, when His people keep His testimonies and ordinances.