Psalms 90:3

“Upon an instrument of ten strings, etc.] An harp of ten strings, as the Targum. The harp invented by Terpander had only seven strings f1327; according to Pliny f1328; Simonides added the eighth, and Timotheus the ninth; but this of David was of ten strings: and upon the psaltery; of which (see Gill on “<193302>Psalm 33:2”), “upon the harp with a solemn sound”; or “upon higgaon with the harp”; which “higgaon”, Aben Ezra says, was either the tune of a song, or an instrument of music; all these instruments of music were typical of the spiritual joy and melody which the saints have in their hearts when they praise the Lord; hence mention is made of harps in particular in this spiritual sense,…”

“Thou turnest man to destruction - In contradistinction from his own unchangeableness and eternity. Man passes away; God continues ever the same. The word rendered “destruction” - דכא dakkâ' - means properly anything beaten or broken small or very fine, and hence, “dust.” The idea here is, that God causes man to return to dust; that is, the elements which compose the body return to their original condition, or seem to mingle with the earth. Genesis 3:19 : “dust thou art, and unto dust shalt thou return.” The word “man” here, of course, refers to man in general - all people. It is the great law of our being. Individual man, classes of people, generations of people, races of people, pass away;…”

“Turnedst - But as for man, his case is far otherwise, though he was made by thee happy. and immortal, yet for his sin thou didst make him mortal and miserable. Saidst - Didst pronounce that sad sentence, return, O men, to the dust out of which ye were taken, Gen 3:19. Psalms 90:4”

“90:3-6 Unlike God, humans are mortal and transitory.”

“Thou: Psa 104:29, Psa 146:4; Gen 3:19, Gen 6:6, Gen 6:7; Num 14:35; Job 12:10, Job 34:14, Job 34:15; Ecc 12:7 Return ye children of men: Rather, "Return ye children of Adam;" i.e., to that dust out of which ye were originally formed. Psalms 90:4”