He told his disciples how they were to act if they chose to fast, but he never commanded that they fast. (Matthew 6:16-18; 9:14)

It would also be a mistake to publicize the fact that you fast or to fast because another person tells you to do so. According to Matthew 6:16-18, Jesus counseled that fasting should be a private matter, between you and God, and that you should not announce it to others.