These heavenly entities should praise Yahweh because He created them all by His command. The order of creation in this psalm generally follows the order of Genesis 1 , though the writer took some poetic liberty. Furthermore, these created things continue to exist as they do because God made a decree that they should endure as long as He wills. The Canaanites worshipped the stars and planets, so this psalm would have been a polemic against their idolatry. [source][source][source]