Praise the LORD from the earth, ye {e} dragons, and all deeps:

(e) Meaning the great and monstrous fishes, as whales and such like.

Wesley's Notes

148:7 Dragons - Either serpents, which hide in the deep caverns of the earth; or whales, and other sea - monsters, which dwell in the depths of the sea.

Jamieson-Fausset-Brown Bible Commentary

7-10. The call on the earth, as opposed to heaven, includes seas or depths, whose inhabitants the dragon, as one of the largest (on leviathan, see on [636]Ps 104:26), is selected to represent. The most destructive and ungovernable agents of inanimate nature are introduced.

Matthew Henry's Concise Commentary

148:7-14 Even in this world, dark and bad as it is, God is praised. The powers of nature, be they ever so strong, so stormy, do what God appoints them, and no more. Those that rebel against God's word, show themselves to be more violent than even the stormy winds, yet they fulfil it. View the surface of the earth, mountains and all hills; from the barren tops of some, and the fruitful tops of others, we may fetch matter for praise. And assuredly creatures which have the powers of reason, ought to employ themselves in praising God. Let all manner of persons praise God. Those of every rank, high and low. Let us show that we are his saints by praising his name continually. He is not only our Creator, but our Redeemer; who made us a people near unto him. We may by the Horn of his people understand Christ, whom God has exalted to be a Prince and a Saviour, who is indeed the defence and the praise of all his saints, and will be so for ever. In redemption, that unspeakable glory is displayed, which forms the source of all our hopes and joys. May the Lord pardon us, and teach our hearts to love him more and praise him better.