Sefer ha-Bahir, widely considered the first kabbalistic text, was finalized in southern France during the end of the twelfth century. Its author is unknown. Bahir means “bright” or “clear,” which is ironic because the text is extremely dense and difficult. Written in a mixture of Hebrew and Aramaic, Sefer ha-Bahir divides into two parts.

The first part is a discussion of the Sefer Yetzirah written in a choppy, haphazard style. The second is an attempt to clarify the order of the sefirot, which the Sefer Yetzirah describes as ten numbers. In the Sefer ha-Bahir the sefirot are described for the first time as “emanations” or attributes of God. In addition to representing a particular part of God, each sefirah also corresponds to a stage in creation and a character from the Bible.

Another concept that the Sefer ha-Bahir introduces for the first time is the Tree of Life, a visual representation of the ten sefirot. The Sefer ha-Bahir describes the locations of each sefirah on the Tree of Life—left side, middle, and right side—and reveals which objects on Earth embody that sefirah’s qualities. (See below for a fuller description of the sefirot). The Tree is intended to symbolize the body of “Adam Kadmon,” also known as “primordial Adam.” Adam Kadmon is not the Adam of “Adam and Eve” that we read about in Genesis, but a kind of mystical template for human beings that God made before creating everything else. Though he never existed in the human world, Adam Kadmon was God’s most important creation. He also serves as the first example of man being created in God’s image: as a product of God, Adam Kadmon was a part of God. The Tree, the body of Adam, and the spiritual form of God are linked symbolically in visual diagrams of the ten sefirot.

Kabbalah is in many ways a religion that thrives on thoroughness and obscurity at once. As they tried to unravel the mysteries of the universe, such as creation and the birth of humankind, kabbalists argued for centuries over passages in the Torah. The closer they looked at words, the more mysterious truths about the universe became. Though exceptionally difficult, the Sefer ha-Bahir arranged and organized Kabbalah’s sprawling ideas into a coherent form in one volume. Most important, it explained that the sefirot are aspects of God’s personality, not just numbers. The sefirot represent God’s best attributes, such as wisdom, mercy, and beauty, and kabbalists believe they represent the core components of successful societies and fulfilling lives.

The sefirot don’t correspond to places on Adam Kadmon’s body, or on God’s body, since neither God nor Adam Kadmon ever existed in physical form. For kabbalists, however, different parts of our bodies have different essential qualities—the head represents wisdom, the heart stands for mercy and beauty, and so on. So linking a sefirah to a part of the mystical form of God was a way of reinforcing the underlying qualities of that sefirah. Therefore Keter, the crown, is associated with the head and therefore with wisdom. Yesod, another sefirah, represents the penis and is associated with the “foundation,” or source, of man.

The Sefer ha-Bahir shows how deeply followers of Kabbalah believed in the practice of close reading, especially with regard to the Torah. They believed that hidden in the language of the Torah were clues to the creation of the universe and links to each sefirah. For example, the story of the exodus of the Jews from slavery in Egypt could be read to contain hidden clues about the unfolding of the sefirah Netzach, which means “loyalty” or “endurance.” Characters in the Bible often embody qualities associated with each sefirah—such as Moses representing Netzach. For this reason, each sefirah is linked not just to the stages of creation, the body of Adam Kadmon, and the form of God, but also to characters in the Bible.