For he knoweth our frame,.... The outward frame of their bodies, what brittle ware, what earthen vessels, they be; he being the potter, they the clay, he knows what they are able to bear, and what not; that if he lays his hand too heavy, or strikes too hard, or repeats his strokes too often, they will fall in pieces: he knows the inward frame of their minds, the corruption of their nature, how prone they are to sin; and therefore does not expect perfect services from them: how impotent they are to that which is good; that they can do nothing of themselves; nor think a good thought, nor do a good action; and that their best frames are very uncertain ones; and that, though the spirit may be willing, the flesh is weak.
The word used is the same that is rendered "imagination", Ge 6:5, and by which the Jews generally express the depravity and corruption of nature; and so the Targum here paraphrases it,"for he knows our evil concupiscence, which causes us to sin;''and to this sense Kimchi.
He remembereth that we are dust ; are of the dust originally, and return to it again at death; and into which men soon crumble when he lays his hand upon them; this he considers, see Ps 78:38. The Targum is,"it is remembered before him, that we are of the dust:''the Septuagint version makes a petition of it, "remember that we are dust"; and so the Arabic version.
And we should remember it ourselves, and be humble before God; and wonder at his grace and goodness to us, Ge 18:27. "Pulvis et umbra sumus", Horat. Carmin. l. 4. Ode 7. v.