Yom Kippur is the most sacred holiday of the Jewish year. It is also unique among the holidays. All of the other feasts and fasts either commemorate a decisive event in Jewish history or mark turning points in the rhythm of the agricultural year.

But Yom Kippur is different. It commemorates no historical event. It has no agricultural associations. It points to nothing beyond itself. The meaning and importance of the day derives not from what it remembers or appreciates, but from what happens on this day.

What is the event of Yom Kippur? “For on this day atonement shall be made for you, to cleanse you; from all your sins you shall be clean before Hashem” (Lev 16:30). On Yom Kippur God forgives, purifies, renews. The holiday does not merely thank God for doing this generally and at all times. God does it on Yom Kippur!