Why Do Jews Fast on Yom Kippur?

The Yom Kippur fast is perhaps the most widely observed Jewish practice, even among many Jews who are not otherwise strictly observant. But why fast? What purpose does physical affliction serve on the Day of Atonement?

The Biblical Command

The Torah commands:

וְעִנִּיתֶם אֶת נַפְשֹׁתֵיכֶם

Translation: You shall afflict your souls. (Leviticus 16:29)

to mean abstaining from food and drink, as well as the other four prohibitions of Yom Kippur.

Reasons for Fasting

Focus on the Spiritual

By setting aside physical needs, we devote ourselves entirely to spiritual matters. Without meals to prepare, cook, and eat, the entire day becomes available for prayer and reflection.

Humility Before God

Fasting reminds us of our mortality and dependence on God. We cannot sustain ourselves; we rely on divine blessing for every breath and morsel.

Resembling Angels

On Yom Kippur, we transcend our physical nature and imitate the angels who have no bodily needs. Dressed in white, abstaining from food, we aspire to purely spiritual existence.

Sympathy with the Suffering

Hunger connects us to those who suffer want. The fast should awaken compassion and inspire charitable action.

Physical Repentance

Just as we repent with words and intentions, the body participates through its own discipline and discomfort.

Who Is Exempt?

The same Torah that commands fasting also commands preserving life. Those whose health would be endangered by fasting are prohibited from doing so:

Serious Illness

Anyone with a medical condition where fasting poses risk.

Pregnancy and Nursing

When fasting might endanger mother or child.

Children

Under bar/bat mitzvah age, though older children may practice partial fasting.

The Meaning Beyond Hunger

The fast is not meant as punishment but as liberation—freedom from the constant demands of the body to pursue higher concerns. As Isaiah proclaims, the true fast God desires is one that leads to justice and compassion (Isaiah 58).

Breaking the Fast

The joy of breaking the fast represents renewal. Having been cleansed, having afflicted our souls, we return to physical life with fresh perspective, ready to eat and drink in holiness.