Zechariah 7:6 - Albert Barnes' Notes on the Bible

And when ye eat and when ye drink, is it not ye who eat and ye who drink? - Conversely now that, after your return, ye feast for joy, this is no religious act; ye have all the good of it, there is no thanksgiving to God. Contrary to the apostle’s saying, “Whether ye eat or drink, or whatever ye do, do all to the glow of God” 1 Corinthians 10:31. “He eateth and drinketh to himself, who receiveth the nourishments of the body, which are the common gifts of the Creator, without the needy. And anyone fasts to himself, if he doth not give to the poor what for the time he withdraweth from himself, but keepeth it to be thereafter offered to his appetite. Hence, it is said by Joel, sanctify a fast. For to ‘sanctify a fast’ is to show an abstinence worthy of God through other good deeds. Let anger cease, quarrels be hushed. For in vain is the flesh worn, if the mind is not refrained from evil pleasures, since the Lord says by the prophet, “Behold, in the day of your fast ye find pleasure. Behold, ye fast for strife and debate ...” Isaiah 57:3-4.