Matthew 6:16-18

“When you fast, don’t put on a sad face like the hypocrites. They make their faces look sad to show people they are fasting. I tell you the truth, those hypocrites already have their full reward. So when you fast, comb your hair and wash your face. Then people will not know that you are fasting, but your Father, whom you cannot see, will see you. Your Father sees what is done in secret, and he will reward you.