Isaiah 58:5

Should such be the fast that I choose? Can mere gestures and symbols of humiliation avail anything, along with such evidences of an unspiritual frame of mind?

to afflict his soul Both here and in Isaiah 58:3 the phrase expresses what is of moral value in the act of fasting, the repression of sensual impulses through abstinence, &c. It is so used also in Psalms 35:13 ("I humbled my soul through fasting"), and in the laws about fasting it becomes almost a technical expression (Leviticus 16:29; Leviticus 16:31; Leviticus 23:27; Leviticus 23:32; Numbers 29:7). From it comes the noun ta-anîth(humiliation), the common term for fasting in late Hebrew (found Ezra 9:5). How little the true end of fasting was attained in the case of those here addressed has been shewn in Isaiah 58:4.