Fasts in the Bible
Periodic fasts
The sole fast required by the law of Moses was that of the great Day of Atonement, Leviticus 23:26-32. It is called “the fast” (Acts 27:9).
The only other mention of a periodical fast in the Old Testament is in Zechariah 7:1-7; 8:19, from which it appears that during their captivity the Jews observed four annual fasts.
The fast of the fourth month, kept on the seventeenth day of Tammuz, the anniversary of the capture of Jerusalem by the Chaldeans; to commemorate also the incident recorded Exodus 32:19. (Compare Jeremiah 52:6-7.)
The fast of the fifth month, kept on the ninth of Ab (compare Numbers 14:27), to commemorate the burning of the city and temple (Jeremiah 52:12-13).
The fast of the seventh month, kept on the third of Tisri (compare 2 Kings 25), the anniversary of the murder of Gedaliah (Jeremiah 41:1- 2).
The fast of the tenth month (compare Jeremiah 52:4; Ezek. 33:21; 2 Kings 25:1), to commemorate the beginning of the siege of the holy city by Nebuchadnezzar.
Special national fast
There was, in addition to these, the fast appointed by Esther (4:16).
Public national fasts
Public, national fasts held on account of sin or to supplicate divine favor were sometimes held.
Local fasts
There were also local fasts.
Private fasts
There are many instances of private, occasional fasting (1 Samuel 1:7; 20:34; 2 Samuel 3:35; 12:16; 1 Kings 21:27; Ezra 10:6; Neh. 1:4; Dan. 10:2-3). Moses fasted forty days (Exodus 24:18; 34:28), and so also did Elijah (1 Kings 19:8). Our Lord fasted forty days in the wilderness (Matthew 4:2).
Hypocritical fasts
Over time, the practice of fasting was lamentably abused (Isaiah 58:4; Jeremiah 14:12; Zechariah 7:5). Our Lord rebuked the Pharisees for their hypocritical pretences in fasting (Matthew 6:16). He himself appointed no fast.
Christian fasts
The early Christians, however, observed the ordinary fasts according to the law of their fathers (Acts 13:3; 14:23; 2 Corinthians 6:5).