In the end, neither the Zohar, nor the writings of the Ari were intended for a systematic study of the Kabbalah. Although the Kabbalah is indeed a science, before the 20th century there never was a real textbook. In order to fill in the gaps, Rabbi Yehuda Ashlag, the great Kabbalist who lived in Jerusalem since 1922 until his death in 1954, wrote a commentary on the Zohar and the texts of the Ari. He evolved while writing the commentaries, and published his principal work, The Study of the Ten Sefirot (Talmud Eser Sefirot), considered the predominant study book of our time.
It is only in our days that the great Kabbalist, Rabbi Yehuda Ashlag established the comprehensive and concise method suitable for all souls that descend to this world. Rabbi Yehuda Ashlag was born in Warsaw in 1885 and came to Jerusalem in 1922. He was appointed the rabbi of one of the neighbourhoods in Jerusalem, and began to write his composition, The Study of the Ten Sefirot. He gave his composition this name, because the spiritual world and this world, the souls in the upper worlds and indeed the entire universe, are all comprised of ten Sefirot.
This textbook consists of six volumes, containing more than two thousand pages. It includes everything that Kabbalists have written since the dawn of time, i.e. the writings of the First Man, Abraham the Patriarch, Moses, Rabbi Shimon Bar-Yochay and the holy Ari. This book displays Kabbalah in a concise manner, fit for study. Thus, we have with us today everything needed to learn how creation was made, how it comes down to us and how we can influence it from below all the way to the highest world, to have the future we’d like to have. This is why today Kabbalists study only the books of Rabbi Yehuda Ashlag.
When we learn from The Study of the Ten Sefirot under the right conditions, meaning in the right way and under the right guidance, the upper world opens. There is a special approach to the material in the book, and a special key that explains how to read the text, to make it open correctly. When a person studies like that, he begins to feel the universe, to see and feel in every sense what exists beyond the range of that sense, because his senses are corporeal and limited, and can perceive nothing beyond their scope.
Rabbi Yehuda Ashlag, called Baal HaSulam, writes in the introduction to the Study of the Ten Sefirot, that thanks to the permission to write the book that he received from above, anyone can attain the highest point of evolution of his soul in our world, anyone can attain equivalence of form with the upper force, i.e. the Creator. We can attain the highest spiritual situations while living in this world, because the body no longer stands as a barrier between one and one’s soul. It doesn’t matter if one’s soul is clothed in a body or not, because one can freely move from world to world, exist in all the worlds simultaneously, in a state of eternity and perfection. Then, one becomes timeless, motionless, and spaceless.
Baal HaSulam writes that using his method makes all these situations attainable; he writes that his method is suitable for everyone without exception. Besides the Study of the Ten Sefirot, he also wrote a commentary on the Zohar, and the writings of the Ari. Baal HaSulam writes about himself, that he is a reincarnation of a soul that starts with the First Man, continues through Abraham the Patriarch, Moses, Rabbi Shimon Bar-Yochay, the Ari and finally him. Because of that he could take the compositions of these Kabbalists, process and present them to us in way that suits our generation.
Although Baal HaSulam lived in our generation, what happened to his writings is much the same as what happened with the Zohar and the writings of the Ari: some of his writings were concealed and are only now being published. I too have many manuscripts of Baal HaSulam that my students and I prepare for publication. They are manuscripts that I received as spiritual inheritance from my rabbi, Baruch Ahslag.