How to Fast

Fasting in the OT

Apart from the Day of Atonement, fasting is absent from the Pentateuch but appears throughout the rest of the Old Testament. Fasting is frequently performed along with other practices of mourning, lamentation, or penitence, and it often is conjoined with prayer. At times, fasting functions as a preventative measure prior to engaging in dangerous activity, such as a journey or battle.

In the Old Testament, people often tear their clothes and dress in sackcloth and ashes as they fast (e.g., 2 Sam 1:11–12; Dan 9:3; Esth 4:3). Such activities mark the participants as being in a lowly state and indicate weakness; fasting is a means of physically lowering oneself.

The Lexham Bible Dictionary The Day of Atonement

The Day of Atonement

The Mosaic law contains only one command to fast, connected with the Day of Atonement (Lev 16:29–31; 23:26–33; Num 29:7–11). The Hebrew text does not use the word for fast (צוֹם, tsom), but instead uses עָנָה (anah), which is often translated as “deny yourself” (NRSV). This more general reference may imply that other forms of self-denial were also intended, such as abstinence from contact with the opposite sex, from anointing with oil or bathing, or from wearing sandals (Yoma 8:1; Hartley, “Atonement,” 58).

The term עָנָה (anah) also means “to afflict,” “to weaken,” “be humble,” or “be bowed down” (BDB, 776). On a day when the sins of the people were to be atoned for, afflicting or denying oneself by fasting would serve as an outward sign of inner repentance for breaking God’s law (Brongers, “Fasting in Israel,” 15). Another purpose of this fast may have been the belief that the temporary suspension of normal activities such as eating allowed one to focus on God and acknowledge dependence on Him

Examples of Fasting in the Old Testament

Fasting Associated with Repentance and Confession

1 Sam 7:6

The Israelites fast as a way of turning away from foreign gods and back to the Lord.

Neh 9:1–2

The Israelites fast and confess their sins once all the foreigners are removed from their community.

Jonah 3:4–9

The Ninevites fast when they learn that the city will be overturned in 40 days.

Fasting in Association with Mourning

1 Sam 31:12

When Saul and his sons are killed in battle, the men of Jabesh-Gilead fast.

2 Sam 1:12

David and his men fast when they learn of Saul’s death.

Fasting in Association with Danger

Judges 20:26

The Israelites fight the tribe of Benjamin. Despite having more soldiers, they are losing, so they return to their camp and fast and weep. The result is that the Lord defeats the Benjaminites (Judg 20:35).

2 Chr 20:1–3

When the Moabites and Ammonites come up against Jehoshaphat in battle, Jehoshaphat proclaims a fast in Judah. The Lord brings victory (2 Chr 20:22).

Ezra 8:21–23

A fast is proclaimed prior to the return journey from Babylon to Judaea.

Neh 1:4

Nehemiah fasts when he hears that the gates of Jerusalem have been destroyed and the captives are in danger.

Esth 4:3

When Haman’s decree to kill the Jews reaches the provinces of the king, there is mourning and fasting for the Jews.

Esth 4:16

Esther, who is about to risk her life by seeking an audience with the king, proclaims a three-day fast for all the Jews in Susa.

Joel 1:13–15

Joel prophesies the day of the Lord which will bring destruction. The audience is told to lament and sanctify a fast.

The Lexham Bible Dictionary Fasting in the New Testament

Fasting in the New Testament

In the New Testament, fasting occurs primarily in the Gospels, where it is a regular practice of John, his disciples, and the Pharisees (Matt 9:14; Mark 2:18; Luke 5:33; 18:12). Jesus fasts for 40 days during His temptation in the wilderness. Luke and Acts depict fasting as a part of worship (Luke 2:37; Acts 14:23).

Jesus and Fasting

The Gospels record Jesus fasting, perhaps to express reliance on God in times of temptation or spiritual warfare (e.g., Matt 4:1–2; Luke 4:2). Although Mark’s description of Jesus’ temptation omits any reference to fasting, he does describe angels caring for Jesus (Mark 1:13), which may suggest that Jesus was receiving heavenly food in the wilderness.

In the Sermon on the Mount (Matt 6:16–18), Jesus criticizes those who fast hypocritically in order to attract attention. He tells people to give alms, pray, and fast in ways that are visible only to God. They should not mar their faces or look gloomy; instead, they should wash their faces and put oil on their heads so that only God knows they are fasting.

Because the Pharisees fasted, as did disciples of John the Baptist, Jesus’ disciples were unusual for not fasting (Matt 9:14–15; Mark 2:18–20; Luke 5:33–35). Jesus defends this behavior using a parable of a bridegroom. He indicates that His presence, like a bridegroom’s, was a cause for celebration, making fasting inappropriate. According to Jesus, a time for mourning (and fasting) would be fitting when the bridegroom is taken away (Matt 9:15; Mark 2:20; Luke 5:34).

Fasting in Acts

The earliest Christian fasts seem to have been voluntary and were undertaken for a variety of reasons, such as self-discipline and reinforcement while praying. Calling for God’s blessing on the church’s mission, the church at Antioch engaged in fasting before sending out missionaries (Acts 13:2–3) and in connection with the appointment of presbyters (Acts 14:23).

Fasting in the Early Church

A number of Christian authors comment on fasting, indicating that it was widely practiced by the church before the middle of the third century (Brattston, “Fasting,” 238). Various Christian documents reference fasting as an ongoing practice. While the Didache encourages fasting and mentions a twice-weekly fast (Did., 8:1), the Shepherd of Hermas conveys that obedience is more righteous than fasting (Shepherd of Hermas, Similtude 5:1–4).

The early church fathers might have believed that fasting could conquer temptations (Polycarp, Phil, 7:2) and prepare people for worship (Origen, Hom. Lev., 7.1.3; Brattston, “Fasting,” 239). Certain texts recommend fasting before baptism (Did., 7:4; Tertullian, Bapt., 20).