For the source text click/tap here: Yoma 55
To download, click/tap here: PDF
The Kohen Gadol stood facing the two poles of the Ark and sprinkled the blood toward it and the kaporet – once upward and seven times downward. He sprinkled the bull’s blood first, followed by the goat’s blood. The sprinkling of blood expresses our devotion to our covenantal bond with God, for blood is life; the blood of the bull represented the blood of the kohanim and the Kohen Gadol, while the blood of the goat represented the blood of Israel.
Rav Chayim Soloveitchik (in his chiddushim to the gemara) claimed that even after the aron was buried, the location still maintained the unique sanctity of the aron. This view would still allow us to define the sprinkling as aron-related; even though no physical aron existed, the location was still imbued with the unique status of the aron.
Each of the seven downward sprinklings, counted one to seven, is preceded by "one," referring to the upward one. This remarkable method of counting, which the chazzan and kahal recite responsively and repeatedly on Yom Kippur, teaches that one may not be involved in earthly matters without the pervasive influence of heavenly ideals.
This leads us to an intriguing Vatican inquiry of late and its response.