וְׁלָקַח מִ דַם הַפָר וְׁהִ זָה בְׁ אֶצְׁ בָעוֹ עַל-פְׁ נֵי הַכַפֹּרֶ ת קֵדְׁ מָה וְׁלִפְׁ נֵי הַכַפֹּרֶ ת יַזֶה שֶ בַע-פְׁעָמִ ים מִ ן-הַדָם בְׁ אֶצְׁ בָעוֹ: וְׁלָקַח מִ דַם הַפָר וְׁהִ זָה בְׁ אֶצְׁ בָעוֹ עַל-פְׁ נֵי הַכַפֹּרֶ ת קֵדְׁ מָה וְׁלִפְׁ נֵי הַכַפֹּרֶ ת יַזֶה שֶ בַע-פְׁעָמִ ים מִ ן-הַדָם בְׁ אֶצְׁ בָעוֹ: (ויקרא טו, יד)
Yuma 53b: The Kohein Gadol went in (with the Dam which was being stirred) and did the Zerikas Dam ha'Par in the Kodesh haKodoshim. The Haza'ah was one upward and seven downward (not on the Paroches but on the ground below) while counting aloud. The Even ha'Shesiyah stood where the Aron once stood (no Aron in the 2nd Bais haMikdash).
The second time the Kohain Gadol enters the Kodesh HaKodoshim on Yom Kippur, he stands before the Aron Hakodesh and sprinkles the blood of the bull from his own Chatas, with his finger. The Kohain Gadol counts out loud and in an interesting way. With his finger he sprinkles toward the Aron Hakodesh (Holy Ark) once upward and seven times downward, counting loudly. He sprinkles with force and does not let it drip.
Again the Kohain Gadol leaves the Kodesh HaKodoshim backwards. Once he enters the Kodesh he sprinkles some of the bull's blood and then some of the goat's blood on the Paroches (curtain) of the Kodesh HaKodoshim, once up and seven times down, counting loudly.
The third time the Kohain Gadol enters the Kodesh HaKodoshim he stands before the Aron Hakodesh (Holy Ark) and sprinkles the blood of the "L'Hashem" goat with his finger toward the Aron Hakodesh (Holy Ark), once upward and seven times downward, counting loudly. Again the Kohain Gadol leaves the Kodesh HaKodoshim backwards.
The plain intent of the Pasuk is that the Kohein Gadol sprinklers eight times on the Kapores (once on the upper portion and seven times on the lower portion). However, Chaza”l (Sukkah 55a) state that none of the blood is actually sprinkled on the Kapores. Rather the blood is sprinkled in the direction landing on the ground (according to the Aruch in the same place; according to Rashi the one upward landed further away). The intention is not above or below, but is applied like a whip (that sprays in a directional manner). The term above and below applies to the position of the finger prior to the sprinkling.
Further, Chaza”l teach that the Kohein Gadol counts as he apples the blood. One when the finger is in an upwards position. And then when the finger is in the downwards position, he counts one and one, one and two, etc. “Before the Kapores יזה” singular, telling us the first one is counted together with each of the others (and thus not count one through eight). The repeating of the “one and” allows the Kohein Gadol time to intent his heart between each sprinkle.
Commentaries
Chizkuni: seven times in order to atone for their seven sins (as in the Tochacha where punishments were in groups of seven reflecting the group of seven sins.
Bnei Yissacar: the Pasuk says to apply 40 lashes when performing the actual act of whipping, but the Bais Din only does 39. This indicates that even when applying judgment one must do so with a measure of mercy (after 39 times is as if started the fortieth and thus, fulfilled the principal). So when applying the blood as atonement for the sins of the Jews, the Kohein Gadol applies like a whip (does not reach the Kapores) to express the principal that one who needs punishment should only receive the least necessary and not have the full amount.
Maharal: seven represents the natural world and its influences; one reflects that the Jews were above nature.
Rema: the one upwards refers the good inclination of a person that pushes one to the One above. The seven downwards reflects the evil inclination which has seven names (types) and drags a person downwards. Say “one” each time that the good inclination should have a positive influence on each evil inclination.
Sefes Emes: the root of all spiritual revelations (such as the seven Clouds of Glory revealed on Sukkos) is the service of the Kohein Gadol on Yom Kippur. Thus, the one upwards represents the avodah of Yom Kippur when all Jews are uplifted, and the seven downwards represents the seven days of Sukkos which represents the actions involving drawing down of holiness into the physical activities such as eating and sleeping in the Sukkah. The goal is to connect to the “once upwards” so as not to fall “seven times downwards.”