5. 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" (Mt 6:17, 18; 1Ki 21:27; Es 4:3).