St. John Chrysostom on Fasting

The value of fasting consists not only in avoiding certain foods, but in giving up of sinful practices. The person who limits his fast only to abstaining from meat is the one who especially lowers the value of it.

Do you fast? Prove it by doing good works. If you see someone in need, take pity on them. If you see a friend being honored, don't get jealous of him. For a true fast, you cannot fast only with your mouth. You must fast with your eyes, your ears, your feet, your hands, and all parts of your body.

You fast with your hands by keeping them pure from doing greedy things. You fast with your feet by not going to see forbidden shows or plays. You fast with your eyes by not letting them look upon impure pictures. Because if this is forbidden or unlawful, it mars your fast and threatens the safety of your soul. But if you look at things which are lawful and safe you increase your fast, for what you see with your eyes influences your conduct. It would be very stupid to eliminate or give up meat and other foods because of the fast but feed with your eyes upon other things which are forbidden.

You don't eat meat, you say?  But you allow yourself to listen to lewd things. You must fast with your ears, too. Another way of fasting with your ears is not to listen to those who speak evil or untrue things about others. "Thou shalt not receive an idle report. "  This is especially true of rumors, gossip, untruths which are spoken to harm another.

Besides fasting with your mouth by not eating certain foods, your mouth should also fast from foul language or telling lies about others. For what good is it if you don't eat meat or poultry, and yet you bite and devour your fellow man?