Isaiah
Isaiah 58:5KJV·traditional attribution

Is it such a fast that I have chosen? a day for a man to afflict his soul? is it to bow down his head as a bulrush, and to spread sackcloth and ashes under him? wilt thou call this a fast, and an acceptable day to the LORD?

Matthew Henry Presbyterian

Here we have, I. The displeasure which these hypocrites conceived against God for not accepting the services which they themselves had a mighty opinion of (Isa 58:3): Wherefore have we fasted, say they, and thou seest not? Thus they went in the way of Cain, who was angry at God, and resented it as a gross affront that his offering was not accepted.

Commenting on Isaiah 58:3-7

John Gill Reformed Baptist

Is it such a fast that I have chosen?.... That is, can this be thought to be a fast approved of by me, and acceptable to me, before described, and is as follows: a day for a man to afflict his soul?

Jamieson-Fausset-Brown Reformed

for a man to afflict his soul--The pain felt by abstinence is not the end to be sought, as if it were meritorious; it is of value only in so far as it leads us to amend our ways (Isa 58:6-7). bow . . . head . . . sackcloth--to affect the outward tokens, so as to "appear to men to fast" (Mat 6:17-18; Kg1 21:27; Est 4:3).