Various works (as well as writings whose authors are unknown) have been attributed to R. Bahya. The clarity of R. Bahya's style and his easy exposition have made his books (which draw their material from a variety of sources) popular with the public, particularly his commentary on the Pentateuch which has been published frequently from 1492. In his work R. Bahya interprets the Pentateuch in four ways: literal, homiletical, rational, and according to the Kabbalah. He uses many different sources, beginning with talmudic and midrashic literature, exegetic and philosophic literature, and ending with kabbalistic literature. R. Bahya is considered of great importance in Kabbalah and is one of the main sources through which the kabbalistic sayings of Nahmanides' contemporaries have been preserved. As a rule, Bahya does not divulge his kabbalistic sources. With the exception of the Sefer ha-Bahir, which he considers an authentic Midrash, and Nahmanides, who is his guide in Kabbalah, he rarely mentions other kabbalists, although he uses extensively the writings of R. Jacob b. Sheshet Gerondi, R. Asher b. David, R. Joseph Gikatilla, and others. He treats the Zohar in a similar manner. Parts of the Zohar were known to him, and he copied from them. However, he mentions it only twice (as "Midrash Rabbi Simeon b. Yohai"). Kad ha-Kemah contains alphabetically arranged clarifications on the foundations of faith and had a wide circulation.