“Moreover, when you fast, do not be like the hypocrites, with a sad countenance. For they disfigure their faces that they may appear to men to be fasting. Assuredly, I say to you, they have their reward. 17 But you, when you fast, anoint your head and wash your face, 18 so that you do not appear to men to be fasting, but to your Father who is in the secret place; and your Father who sees in secret will reward you openly.” ~ Matthew 6:16-18.
Jesus condemned the pretentious way of the hypocrites, the Pharisees and other religious leaders, who went out of their way to make a display of their religious acts in an effort to garner public admiration and increase their godliness. Instead, He instructed that fasting should be a humble, intimate period between God and the individual person, not a public display of self-admiration.
“fast” (v.16) — There was only one fast specifically mentioned in the OT, the Day of Atonement (Leviticus 16), which was observed in the seventh month. The Jewish leaders appointed additional fast days to remember specific times of stress in Israel’s national history (Zechariah 7:3-5; 8:19).
“anoint your head” (v.17) — This symbolized rejoicing (Psalm 23:5;45:7; 104:15; Isaiah 61:3), but it was also part of daily routine except when fasting (Daniel 10:3). Not to anoint oneself could be an attempt to appear more pious than others.
“your Father who sees in secret” (v.18) — Our spiritual lives are to be seen primarily by God! We seek His approval, not the approval of men.