Moreover when you fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward. But you, when you fast, anoint your head, and wash your face; That you appear not unto men to fast, but unto your Father who is in secret: and your Father, who sees in secret, shall reward you openly. (Matthew 6:16-18)