Charles H. Spurgeon on Psalms 99:3

Let them praise thy great and terrible name: let all the dwellers in Zion and all the nations upon the earth praise the Lord, or "acknowledge thankfully" the goodness of his divine nature, albeit that there is so much in it which must inspire their awe. Under the most terrible aspect the Lord is still to be praised. Many profess to admire the milder beams of the sun of righteousness, but burn with rebellion against its more flaming radiance: so it ought not to be: we are bound to praise a terrible, God and worship him who casts the wicked down to hell. Did not Israel praise him "who overthrew Pharaoh and his hosts in the Red Sea, for his mercy endureth for ever." The terrible Avenger is to be praised, as well as the loving Redeemer. Against this the sympathy of man's evil heart with sin rebels; it cries out for an effeminate God in whom pity has strangled justice. The well-instructed servants of Jehovah praise him in all the aspects of his character, whether terrible or tender. Grace streaming from the mercy-seat can alone work in us this admirable frame of mind. For it is holy, or He is holy. In him is no flaw or fault, excess or deficiency, error or iniquity. He is wholly excellent, and is therefore called holy. In his words, thoughts, acts, and revelations as well as in himself, he is perfection itself. O come let us worship and bow down before him.