Matthew 6:16

16 `And when ye may fast, be ye not as the hypocrites, of sour countenances, for they disfigure their faces, that they may appear to men fasting; verily I say to you, that they have their reward.

Matthew 6:16 In-Context

14 `For, if ye may forgive men their trespasses He also will forgive you -- your Father who [is] in the heavens;
15 but if ye may not forgive men their trespasses, neither will your Father forgive your trespasses.
16 `And when ye may fast, be ye not as the hypocrites, of sour countenances, for they disfigure their faces, that they may appear to men fasting; verily I say to you, that they have their reward.
17 `But thou, fasting, anoint thy head, and wash thy face,
18 that thou mayest not appear to men fasting, but to thy Father who [is] in secret, and thy Father, who is seeing in secret, shall reward thee manifestly.
Young's Literal Translation is in the public domain.