Matthew 6:18

“That thou appear not unto men to fast, etc.] Which is just the reverse of the hypocrites, the Scribes and Pharisees; and quite contrary to the customs of the Jews, who when they fasted, particularly on their noted fasts f425, “brought out the ark into the street of the city, and put burnt ashes upon it, and upon the head of the prince, and upon the head of the president of the sanhedrim, and every man upon his own head.” All which was done, to be seen of men to fast; but Christ directs to such sorts of fasting, and which is to be done in such a manner, as only to be seen by God: but unto thy Father which is in secret; who is invisible, and who sees what is done in secret, and takes notice of…”

“That thou appear not unto men to fast, but unto thy Father which is in secret: and thy Father, which seeth in secret, shall reward thee openly--The "openly" seems evidently a later addition to the text of this verse from Mat 6:4, Mat 6:7, though of course the idea is implied.”

“But thou when thou fastest, anoint ... - That is, appear as you do daily. Do not assume any new appearance, or change your visage or dress. The Jews and all neighboring nations were much in the habit of washing and anointing their bodies. This washing was performed at every meal; and where it could be effected, the head, or other parts of the body, was daily anointed with sweet or olive oil. In a warm climate, exposed to the great heat of the sun, this practice conduced much to health, preserved the skin smooth and tender, and afforded a most grateful sensation and odor. See Mark 7:2-3; James 5:14; Mark 11:13; John 12:3. The meaning of this whole commandment is, when you regard it to be your…”

“appear: Co2 5:9, Co2 10:18; Col 3:22-24; Pe1 2:13 shall: Mat 6:4, Mat 6:6; Rom 2:6; Pe1 1:7 Matthew 6:19”