16 "And when you fast, don't make it obvious, as the hypocrites do, for they try to look miserable and disheveled so people will admire them for their fasting. I tell you the truth, that is the only reward they will ever get. 17 But when you fast, comb your hair and wash your face. 18 Then no one will notice that you are fasting, except your Father, who knows what you do in private. And your Father, who sees everything, will reward you.
Matthew Henry's Commentary on Matthew 6:16-18
Commentary on Matthew 6:16-18
(Read Matthew 6:16-18)
Religious fasting is a duty required of the disciples of Christ, but it is not so much a duty itself, as a means to dispose us for other duties. Fasting is the humbling of the soul, Psalm 35:13; that is the inside of the duty; let that, therefore, be thy principal care, and as to the outside of it, covet not to let it be seen. God sees in secret, and will reward openly.