וְהִזָּ֨ה עָלָ֧יו מִן־הַדָּ֛ם בְּאֶצְבָּע֖וֹ שֶׁ֣בַע פְּעָמִ֑ים וְטִהֲר֣וֹ וְקִדְּשׁ֔וֹ מִטֻּמְאֹ֖ת בְּנֵ֥י יִשְׂרָאֵֽל׃
And he shall sprinkle of the blood upon it with his finger seven times, and cleanse it, and hallow it from the uncleannesses of the children of Israel.
Read kabbalistic (mystical) interpretation of Leviticus 16:19: and classical mystical sources.