John Gill Commentary James 1:24

"for he beholdeth himself, and goeth away, and straightway forgetteth what manner of man he was." — James 1:24 (ASV)

For he beholdeth himself, and goes his way
He takes a slight glance of himself, and departs:

and straightway forgets what manner of man he was ;
he forgets either his spots, blemishes, and imperfections; or his comeliness and beauty; the features of his face, be they comely or not:

so a bare hearer of the word, who is not concerned to practise what he hears, while he is hearing, he observes some things amiss in himself, and some excellencies in Christ; but, when the discourse is over, he goes his way, and thinks no more of either.