The Lord reigneth - The Lord, Yahweh, is king. See Psa 93:1.
Let the people tremble - The Septuagint and the Latin Vulgate render this, “Let the people rage” - or, be angry: as if the idea were that God reigned, although the people were enraged, and were opposed to him. The true meaning of the word used here, however, is “tremble,” properly signifying to be moved, disturbed, disquieted, thrown into commotion; and then it may mean to be moved with anger, Pro 29:9; Isa 28:21; or with grief, 2Sa 18:33 : or with fear, Psa 4:4; or with joy, Jer 33:9. Hence, it means to be agitated or moved with fear or reverence; and it refers here to the reverence or awe which one has in the conscious presence of God.
He sitteth between the cherubims - See the notes at Psa 80:1.
Let the earth be moved - Margin, “stagger.” The word means to move or quake. It occurs nowhere else. Compare the notes at Psa 18:7. See also Hab 3:6, Hab 3:10.