Jamieson, Fausset and Brown on 1 Peter 1:24

24. Scripture proof that the word of God lives for ever, in contrast to man's natural frailty. If ye were born again of flesh, corruptible seed, ye must also perish again as the grass; but now that from which you have derived life remains eternally, and so also will render you eternal.

flesh--man in his mere earthly nature.

as--omitted in some of the oldest manuscripts.

of man--The oldest manuscripts read, "of it" (that is, of the flesh). "The glory" is the wisdom, strength, riches, learning, honor, beauty, art, virtue, and righteousness of the NATURAL man (expressed by "flesh"), which all are transitory (Joh 3:6), not OF MAN (as English Version reads) absolutely, for the glory of man, in his true ideal realized in the believer, is eternal.

withereth--Greek, aorist: literally, "withered," that is, is withered as a thing of the past. So also the Greek for "falleth" is "fell away," that is, is fallen away: it no sooner is than it is gone.

thereof--omitted in the best manuscripts and versions. "The grass" is the flesh: "the flower" its glory.