ויקרא, פרק ט״ז, פסוק י״ד

At the climax of the Yom Kippur service, the High Priest enters the Holy of Holies to perform the central act of atonement. Standing before the Ark of the Covenant, he carefully sprinkles the sacrificial blood, a precise process designed to purify the sanctuary and secure forgiveness for the Israelites. To begin this process, he steps out into the courtyard to receive the basin of bull's blood from another priest, who has been stirring it continuously to prevent it from clotting. If any portion of the blood were to coagulate, the High Priest must carefully transfer only the usable, liquid blood into another vessel before proceeding [העמק דבר].

The sprinkling itself is performed using the right index finger, with each individual motion requiring a fresh dip into the blood [שפתי כהן, רד צ הופמן]. The High Priest stands between the poles of the Ark and directs the blood toward the eastern face of the Ark cover. This cover serves a specific purpose, as its very name reflects its function of securing atonement for the Israelites [רבנו בחיי]. The direction is universally understood to be eastward, as biblical references to the "front" consistently indicate the east [תורה תמימה, אדרת אליהו].

The primary approach among commentators is that the blood is not sprinkled directly onto the top of the cover, but rather aimed at its front edge so that the drops ultimately fall to the ground. The High Priest applies the blood in a vertical line, placing each drop below the previous one with a whipping motion. When sprinkling upward, he turns the back of his hand downward, and when sprinkling downward, he flips his hand over [רש ר הירש, ביאור יש״ר].

In total, the High Priest performs eight distinct actions: one sprinkle directed upward and seven directed downward, ensuring these are separate motions rather than merely seven drops of blood [תורה תמימה]. The requirement for the single upward sprinkle is understood by some as the simple meaning of the initial instruction to sprinkle, while others derive it by comparing this service to the parallel sprinkling of the goat's blood [רש״י, גור אריה, מזרחי, שפתי חכמים].

As he performs these actions, the High Priest follows a unique counting sequence. Rather than counting consecutively from one to eight, he pairs the initial upward sprinkle with each subsequent downward one, counting aloud: "One; one and one; one and two," and so forth. Some explain this method simply as a practical way to avoid losing count, while others view it as a fundamental obligation to deliberately bind the upper sprinkle to the lower ones [רבנו בחיי, תורה תמימה].

This specific method of counting carries profound symbolic weight. The single upward sprinkle represents complete unity and the connection to God, while the seven downward sprinkles represent the earthly, practical world. By counting them together, the High Priest expresses the essential duty to connect every physical action and worldly advancement to the supreme Divine source. Through this continuous pairing, the entirety of earthly reality is sanctified and bound to the Creator [רש ר הירש, שפתי כהן].