6:16 when ye fast. There is no commandment in the New Testament requiring fasting and only one in the Old Testament, assuming that the command to “afflict your souls” on the Day of Atonement (Leviticus 16:29) refers to fasting. However, voluntary fasting is appropriate on special occasions of great concern or need, provided that the motivation is not just to appear spiritual to other people but to pray more single-mindedly to God.