Psalm 33 has no title in the text. It is a hymn of praise that calls the righteous to rejoice in Yahweh with lyre, harp of ten strings, and a new song played skillfully with a shout of joy. Praise is fitting for the upright, the psalm says, because Yahweh's word is right and all his work is done in faithfulness. He loves righteousness and justice, and the earth is full of his loving kindness.
The psalm then celebrates creation by word alone. By Yahweh's word, the heavens were made: all their army by the breath of his mouth. He gathers the seas and stores the deeps. Let all the earth fear Yahweh, for he spoke, and it was done. He commanded, and it stood firm. In the New Testament, John says that all things were made through the Word (John 1:1-3).
Finally, the psalm contrasts human power with God's care. Yahweh brings the counsel of the nations to nothing, but the counsel of Yahweh stands fast forever. He looks from heaven, sees all people, and fashions their hearts. There is no king saved by the multitude of an army, and a horse is a vain thing for safety. But Yahweh's eye is on those who fear him, to deliver their soul from death and keep them alive in famine. So the people say, Our soul has waited for Yahweh. He is our help and our shield, and they pray, Let your loving kindness be on us, Yahweh, since we have hoped in you.