Caution in the Study of Kabbalah

Rav Yo'ir Chaim held that Kabbalah is very holy, but that it carries great theological danger, and should therefore be studied only by the extremely pious and only with a teacher. In his responsa he relates that a commoner asked him to explain the Kabbalistic formulas commonly printed in the siddur. He refused to answer, and when pressed said only that he did not know the explanation. Although he discouraged in-depth study of Kabbalah, he encouraged the simple reading of the Zohar.