O Lord, how manifold are thy works! - literally, “how many.” The reference is to the “number” and the “variety” of the works of God, and to the wisdom displayed in them all. The earth is not suited up merely for one class of inhabitants, but for an almost endless variety; and the wisdom of God is manifested alike in the number and in the variety. No one can estimate the “number” of beings God has made on the earth; no one can comprehend the richness of the variety. By day the air, the earth, the waters swarm with life - life struggling everywhere as if no placc was to be left unoccupied; even for the dark scenes of night countless numbers of beings have been created; and, in all this immensity of numbers, there is an endless variety. No two are alike. Individuality is everywhere preserved, and the mind is astonished and confounded alike at the numbers and the variety.
In wisdom hast thou made them all - That is, Thou hast adapted each and all to the different ends contemplated in their creation. Anyone of these beings shows the wisdom of God in its formation, and in its adaptations to the ends of its existence; how much more is that wisdom displayed in these countless numbers, and in this endless variety!
The earth is full of thy riches - Hebrew, “possessions.” So the Septuagint and the Vulgate. That is, these various objects thus created are regarded as the “possession” of God; or, they belong to him, as the property of a man belongs to himself. The psalmist says that this wealth or property abounds everywhere; the earth is full of it.