Fasting In The Israelite Tradition


The only fast day actually ordained in Torah is at the Day of the Atonements (Yom ha-Kippurim). On this day we fast from sunset to sunset. We deny ourselves any form of nourishment. Fasting on this day takes the place of the offering of sacrifices, and forms part of the act of prayer.

Fasting involves ‘afflicting the soul’, which is the Hebrew way of saying ‘starving the appetite’. Anything that has nutritional value must not pass our lips. The human body can survive without food for a day without any damage to one’s health at all. However, it is dangerous to one’s health to deny oneself water, and can actually do real harm to one’s body. During a fast, we can drink water, but we cannot drink things like juice, wine, milk or beverages.

There are other types of fasts that were practised in ancient times, which were not ordained by Torah: personal fasts as a form of supplicatory prayer; nationwide fasts proclaimed in times of national tribulation; and the four fasts in remembrance of the Babylonian Exile. However, we know that these types of fasts were allowed, because in Numbers 30:14 for example, there is the provision that if a wife fasts for personal reasons, a husband may cancel her vow of fasting.

To retain the holiness (i.e. special distinctiveness) of the fast on the Day of the Atonements, all other personal fasts only last from sunrise to sunset – the hours of daylight. In addition, if Yom ha-kippurim falls on a Sabbath, then we fast on the Sabbath; but if any other fasts fall on a Sabbath, then we fast on the day after. On Yom-ha-Kippurim we do not work, but on the days of any other fasts, we are permitted to work. Lastly, while the fast of Yom ha-Kippurim is obligatory, other fast days are not – they are a personal choice, a form of personal piety.


Attitude to fasting

In the Book of the Prophet Isaiah (58:3), the people questioned the effectiveness of their personal fasts:

“Why have we fasted, and you have not seen it? Why have we starved our bodies, and you have not noticed?”

In the Book of the Prophet Zechariah (7:5), it is recorded that God became displeased with these personal, non-ordained fasts, because the fasts had lost all meaning. God said:

“When you fasted in the Fifth and Seventh Months for the past seventy years, was it really for me that you fasted?”

Why did these fasts so displease God? It is because they still carried on with their unjust ways:

“On the day of your fasting, you do as you please, and exploit your workers. Your fasting ends in quarrelling and strife, and in striking each other with wicked fists. You cannot fast as you do today, and expect your voice to be heard on high.”

(Isaiah 58:3b-4)


The Prophets say that, when we fast for personal reasons, merely denying ourselves nourishment is not enough. What more must we do for our prayers to reach God when we practice personal fasts? This is what God desires of us: we must not think evil in our hearts; we must act justly, feed the poor, and provide them with clothing and shelter:

“Is not this the kind of fasting I have chosen:

To loose the chains of injustice

And untie the cords of the yoke,

To set the oppressed free

And break every yoke?

Is it not to share your food with the hungry

And to provide the poor wanderer with shelter.

When you see the naked, to clothe them,

And not to turn away from your own flesh and blood?”

(Isaiah 58:6-7)


“Administer true justice; show mercy and compassion to one another. Do not oppress the widow or the fatherless, the alien or the poor. In your hearts do not think evil of each other.”

(Zech 7:9-10)


If this is what we do when we fast, then our prayer becomes powerful. It shines out, and has a tremendous effect on the world around us:


“Your light will break forth like the dawn,

And your healing will quickly appear;

Then your righteousness will go before you,

And the glory of YHVH will be your rear guard.

then you will call, and YHVH will answer;

You will cry for help, and God will say: here I am.


Your light will rise in the darkness,

And your night will become like the noonday.

YHVH will guide you always;

He will satisfy your needs in a sun-scorched land

And will strengthen your frame.

You will be like a well-watered garden,

Like a spring whose waters never fail.”

(Isa 58:9-11)


Personal Fasts

Now that we understand what God desires of us during a fast – the right practical things, as well as the right attitude and intent of the heart – we can look at what kind of fasts were embarked upon in biblical times. People often fasted in times of difficulty as a form of prayer for personal reasons. The rabbis came to forbid these types of fasts, because they were heavily abused. A fast is a personal type of prayer of last resort ONLY, and not to be undertaken lightly. A personal fast is only to be undertaken after much deliberation, not be embarked upon on a whim. 

If an ancient Israelite was going through a particularly trying and difficult time, in extreme circumstances they might have chosen to undertake a personal fast to pray for deliverance. Or if they knew that they were about to face a trying time, they might have undertaken a personal fast to pray for strength and courage.

In ancient times, it was even believed that a national fast could avert disaster or God’s displeasure. For example, Jonah was sent to the Assyrians. They were acting wickedly, and disaster was coming their way as a result of their wickedness. However, they repented. They also fasted as part of their repentance, and calamity was avoided.

We know that Pharisees fasted several times a week, but the Prophet Yeshua` was against such rigorous, regular fasting:

“People said to Yeshua`, ‘The followers of Yochanan and the followers of the Pharisees are more virtuous than your followers, because they fast often, and yours don’t.’ So Yeshua` said to them, ‘Can the children of the bridechamber mourn, when their bridegroom’s with them? But believe me I tell you, the days will come when the bridechamber’s taken from them, and then the children will fast!’

(SY 10:1-3)


Fasting is a RARE form of personal piety; it should NOT be turned into something commonplace. It should be reserved for a time when all other prayer has failed; or as a form of special devotion to God’s ways, by purposefully seeking out the poor to help them.

And when we embark on personal fasts, we should not make others realise that we are fasting:

‘When you fast, don’t look sombre like the hypocrites, because they disfigure their appearance so that their fasting might be seen and recognised by others. Rather, when you fast, do your hair, and wash your face, so that no one will know you’re fasting, but only your heavenly Father, who sees what’s done in secret, and will reward you.’

(SY 57:1-2)


The Four Fasts of the Babylonian Exile

There are four fasts mentioned in the books of the Prophets. The prophet Zekharyah says that, when the exiles are returned to the land, and the Temple rebuilt, then:

“the fast of the fourth month, the fast of the fifth month, the fast of the seventh month, and the fast of the tenth month shall become occasions for joy and gladness, happy festivals for the House of Judah.” (Zech 8:19).

The dates and significance of these fasts are as follows (in the chronological order of the events they commemorate):

10th day of the Tenth Month (Tevet) – the two-year siege of Jerusalem by Nebuchadnezzar began in 588 BCE, resulting in a terrible famine for its population (2Kgs 25:1-3, Jer 39:1-2, 52:4. 

17th day of the Fourth Month (Tammuz) – the siege ended in 586 BCE, when the city walls were breached by the Babylonians (2Kgs 25:3, Jer 52:6). I would personally avoid this fast; this is to avoid any sombre religious festivities in the month of Tammuz, which was a sacred month of mourning for Canaanite pagans. The prophet Ezekiel (Ezek 8:14) castigated people for fasting for the pagan fertility god Tammuz during the last two weeks of this month (when the death of Tammuz was commemorated with mourning and fasting), so as Talmidis we avoid the month of Tammuz with regard to any sombre religious festivities, personal fasts etc. In contrast, Orthodox Rabbanites begin a period of mourning on this date, which lasts for 3 weeks.

7th to the 10th day of the Fifth Month (Av) – the destruction of Solomon’s Temple in 586 BCE (2Kgs 25:8-10, Jer 52:12-14). This fast is usually observed on the 9th of Av, because it is also the date when the Second Temple was destroyed in 70 CE. Talmidis restrict this fast to the 9th of Av. 

3rd of the Seventh Month (Tishrei) – Two months later Gedaliah, whom the Babylonian King had put in charge of Judea, and his associates were assassinated at Mitzpah by Ishmael, a member of the royal family opposed to the Babylonian occupation (2Kgs 25:22-25, Jer 40:7-41:3) 

To illustrate as an example, in 2004, these dates occurred on the following days:

17th of Tammuz – 6th July 2004

9th of Av – 27th July 2004

3rd of Tishrei – 19th September 2004 (as the 3rd of Tishrei was a Sabbath)

10th of Tevet – 23rd December 2004



Outside of the Day of the Atonements, fasting is a personal choice, an act of pious devotion and prayer. Personal fasts should not be undertaken lightly. We don’t gain any greater spiritual benefit by fasting more often. 

If we undertake a fast in times of personal trial in order to augment our prayers for deliverance or strength, then it is not enough that we abstain from nourishment. Our fasts must also be accompanied by just behaviour and acts of charity, such as feeding the poor or helping the homeless.

As for the Four Exilic Fasts, they are not simply occasions for mourning the Temple, or remembering the horrors of the Babylonian exile. They are communal opportunities to pray for a better world, and for the just to triumph; and as a community, they are occasions for us to go out into the world together, and help others, together. 

If we go about fasting in the right way – the way that God desires – then our faith ‘will rise in the darkness’, and will shine out ‘like the noonday sun’, and the world will then turn in awe and wonder at the glory of YHVH.