Shorshei Ha-Shemot is considered the most authoritative compilation about Kabbalah Ma'asit (practical Kabbalah), and a standard reference for meditation exercises, spells, amulets, etc. Zacuto collects alphabetically and explains all the holy names, their origin, and their powers. He also gives clear instructions to perform Yechudim (Unions) according to the lurianic tradition, which he learned directly by the emissaries of Safed who came to Italy. He strives to find every possible use and meaning in every ancient manuscript that he could locate, up to the descriptions of the Angelic Alphabets. The reader will find a remedy for every situation. Sometimes, he will be advised to use a plant, sometimes to recite a specific evocation, and sometimes he will have to write a name on a Kosher parchment, wash it with water, and then drink the water. Every recipe is different.