Kabbalah Imamat 16:3: Ohr Ne'erav & Sha'arei Orah

With this shall Aaron come to the holy place (Lev. 16:3)—in order that these two, the righteous [Yesod] and righteousness [Malkhut] should unite as one.

Rather, when is it fitting for him to come? As the next verse continues,²⁹⁴Leviticus 16:3 “With this-Zot-בזאת shall Aharon come into the holy Sanctuary.” That is, with the quality called “This-Zot-זאת” (in the feminine).²⁹⁵That is, with the quality called “This-Zot-זאת” in the feminine, which refers to the quality of Malchut-מלכות, as discussed in the First Gate. This is because the quality called “This is my God-Zeh E”li-זה א״לי” (in the masculine) which is good-Tov-טוב, is bound to her. Therefore, since He is good-Tov-טוב, she therefore is called by His name and is called “This-Zot-זאת” (in the feminine).

If you have been perceptive, you have seen that on Yom Kippur, the singularly special day, the High Priest was granted entry to the innermost sanctum, in order to elicit pardon and forgiveness on behalf of the Jewish people, in addition to blessings and sustenance for the whole year. However, he was only permitted to enter with this quality. This is the meaning of the verse,²⁵⁶Leviticus 16:3 “With this-Zot-זאת shall Aharon come into the Sanctuary.” That is, he only was permitted to enter by means of this-Zot-זאת.