For seven days before Yom Kippur, the high priest lived as if rehearsing for a wedding he could not afford to fumble. Oxen, rams, and lambs were paraded past him one by one so that every motion of the knife, every sprinkling of blood, every angle of approach would be second nature. No detail could go wrong on the day the nation's sins hung on his hands.
He ate well during those seven days, whatever he wanted. But as dusk fell on the eve of the Day itself, the kitchens went quiet. Heavy food would drag him toward sleep, and no one wanted a drowsy priest when the fate of Israel was in the balance.
The elders of the Sanhedrin delivered him like a bride to the elders of the priesthood, who walked him to the Chamber of Abtinas and made him swear a formal oath. My lord high priest, they said, we are ambassadors of the Sanhedrin, and you are our ambassador. We adjure you by Him who dwells in this house: change nothing of what we have taught you.
Then they bid him good night, and both parties wept. He wept because they had treated him as if he might be a Sadducee who would secretly deviate from the ritual. They wept because, according to Torah, those who wrongly suspect the innocent deserve lashes, and they had just suspected their own high priest.
All night they kept him awake. If he was a scholar, he taught; if not, others taught in his presence. They read to him from Job, Ezra, and Chronicles. Zechariah ben Kevootal said, I often read the Book of Daniel before him. And when his eyelids drooped, young priests snapped their fingers and said, My lord, stand up. Cool your feet on the stone floor. They kept him pacing until the first lamb was slaughtered at dawn.
This passage from Yoma 18a-19b, preserved in Hebraic Literature (1901), shows Yom Kippur as the Temple experienced it: a man kept awake by friends who loved him and feared for him, all night long.