This Shabbat (Saturday) Siddur follows the format of The Ari, Rav Isaac Luria, foremost rabbi and Kabbalist sage from the 15th century, considered by many to be the father of contemporary Kabbalah. This Siddur includes Kabbalistic kavanot (intentions) and meditations from the Ari, the Zohar and the Ramchal (Moshe Chaim Luzzatto).