29) In the book "HaB'rit," Part 1, in Chapter 20, the author of "Ma'amar Kuf" writes in the book "Yashar Levav" that the name of the Holy One, blessed be He, is customary on our lips. And when we pronounce the name "Yod-Hey-Vav-Hey" (YHVH), it refers to the countenance of Zer Anpin, who is the Holy One, blessed be He, and whose hidden soul is concealed within him through the inner countenances. He is the very first cause, and it is Him whom we worship in His service.
The general principle, as understood by all the Kabbalists, is that the primary cause, which is referred to by them as "Ein Sof" (the Infinite), is the one who created all existence out of nothingness. He encompasses that entire existence from the outside, and in His chosen aspect, which is the selected aspect among the primordial ancestors, known as Zer Anpin, the concealed dwelling place [14] hidden from the chamber like the soul within the body and enlivening it.
Therefore, this chosen one, Zer Anpin, rules over all creatures, guides them, sustains them, and provides for them. He is our God, and we are with Him because our souls are His portion. He is the one praised in all the praises mentioned in our holy Torah, which He bequeathed to us, and through it, He revealed all the hidden things to us, and so forth. Further evidence from the Zohar and the Tikkunim emphasizes that the service is directed towards Zer Anpin, who is the intermediary that connects everything together.
Furthermore, it is written in the name of the Arizal (Rabbi Isaac Luria) in "Likutei Tanach" regarding the verse "Trust in the Lord forever, for in Yah the Lord is an everlasting rock" (Isaiah 26:4). It is understood that when a person directs their intention solely towards Zer Anpin, it is sufficient, for within that name, Arich Anpin (the Long Face) and Abba (Father) and Ima (Mother) are encompassed, one within the other within Zer Anpin, and so forth.