Answer: And how do we use letters in our world? Do we really have any connection to ZAT of Bina, ZA (Zeir Anpin), and Malchut of the world of Atzilut? It’s known that letters from Aleph to Tet descend from ZAT de Bina; Yod to Tzadik from Zeir Anpin, and Kuf-Resh-Shin-Tav from Malchut, while the final letters MaNTzePaCh stem from the Parsa.
Everything ends at the Parsa of the world of Atzilut, below which lie the worlds of BYA (Beria, Yetzira, Assiya). Below them we have this world, while we exist even lower than that, in our world. So how do we use letters?
The point is that in the world of Atzilut there is a pattern according to which every part of reality divides further more. Hence, no matter where I am, I can use letters according to my spiritual degree.
In France, for instance, in the International Bureau of Weights and Measurements, BIPM, there is a meter gauge made of platinum and iridium. (Incidentally, they decided to stop using the physical model, and from now, a meter is defined based on the consistency of the continuity of the speed of light, as the distance the light travels in a vacuum per 1/299,792,458th of a second.)
Therefore, in our world there are world standards of measurements with which to verify our measuring devices. This allows us to measure objects and distances between them in any place. Likewise, there is the world of Atzilut, where the key model or standard is. It governs how everything is divided and measured in all other worlds. Based on this standard, all other degrees in the world of BYA are built, each of which is a projection of the world of Atzilut, and that is why there are letters in them as well.
Our world is a projection of the upper worlds although its matter has a totally different nature, the egoistic one. Therefore, in our world, we also use letters. Besides, we use the words of our world to describe the spiritual worlds, the so-called “language of branches.”
From the 2nd part of the Daily Kabbalah Lesson 5/26/2011, The Zohar