Note 35 at Mt. 6:17: It was a Jewish custom to anoint yourself with olive oil (Dt. 28:40; Ruth 3:3; 2 Sam. 12:20; 2 Chr. 28:15), and in Jesus' day it was apparently customary to anoint the heads of your guests, also (Lk. 7:46). Sometimes, ointment or perfumes were used in this personal anointing (Amos 6:6; Lk. 7:38; Jn. 12:3). A lack of having your head anointed was associated with mourning or sorrow (2 Sam. 14:2; Dan. 10:3). Therefore, in this verse, Jesus is saying that there should be no external sign of fasting or sorrow, but it should be done secretly to the Lord to receive a full reward.

Paul stated in 1 Corinthians 7:5 that abstinence from the physical relationship in marriage for the purpose of fasting should not be done without the consent of your mate. Therefore, it can be concluded that a fast does not always have to be totally secretive to be productive. Rather, Jesus is once again dealing with the motives behind our actions. The fast must be directed towards God and not men. Compare with the motives spoken of in notes 25-26 at Matthew 6:1 and 3, page 79.