Where does fasting come from?

The custom of fasting on Yom Kippur comes from a passage in Leviticus that says Jews should “Afflict their souls” on Yom Kippur. Rabbis interpreted this to mean that Jews should spend the day devoting their energies towards uninterrupted self-reflection. Fasting thus became the optimal way to slow bodily processes so Jews can focus completely on repentance and communication with the divine.

Why do Jews deny themselves of “luxuries” while fasting on Yom Kippur?

Rabbis note that fasting serves another purpose–as an act of solidarity to recognize the suffering of Jewish people throughout history. This is why Jews are meant to deny themselves of luxuries such as bathing and wearing leather, in addition to food and water.

Do all observant Jews fast?

Most Jewish traditions excuse from fasting those whose health might be negatively impacted such as people with chronic health issues, pregnant women, and children.