Isaiah or Yeshayahu ben Avraham Ha-Levi Horowitz (Hebrew: ישעיה בן אברהם הלוי הורוויץ), (c. 1555 – March 24, 1630), also known as the Shelah HaKaddosh (השל"ה הקדוש‎ "the holy Shelah") after the title of his best-known work, was a prominent rabbi and mystic. Source: Wikipedia (en)