As for man, his days are as grass; As a flower of the field, so he flourisheth.
As for man, his days are as grass. He lives on the grass, and lives like the grass. Corn is but educated grass, and man, who feeds on it, partakes of its nature. The grass lives, grows, flowers, falls beneath the scythe, dries up, and is removed from the field: read this sentence over again, and you will find it the history of man.
David teaches every godly person to thank God first for mercies granted to himself, then for the grace He has given to all His chosen ones through covenant. The Psalmist chiefly magnifies God's mercy in bearing with His people, not because they deserve it, but because He takes pity on their weakness.
AI summary
Commenting on Psalm 103:1-22
[As for] man, his days [are] as grass: as a flower of the field, so he flourisheth. (i) He declares that man has nothing in himself to move God to mercy, but only the confession of his infirmity and misery.