There are various traditions regarding how and when the Ba’al Shem Tov’s brother-in-law met Rav Chaim ben Attar, mechaber of the Ohr HaChaim, in Eretz Yisrael:
After the printing of the chumashim Ohr HaChaim in Venice in the year tov-kuf-bais, they reached the Ba’al Shem Tov, who greatly rejoiced in them. He found in them an author whose heart and soul were filled with emotion and excitement for Avodas Hashem. He sent his brother-in-law, Rav Gershon of Kitov, to Yerushalayim to visit Rav Chaim ben Attar’s Yeshiva. He told Rav Gershon that Rav Chaim ben Attar had two Yeshivos, one where they studied nigle (the revealed Torah) and one where they studied the hidden secrets of Toras HaKabbola. The Ba’al Shem warned Rav Gershon to try to attend the Yeshiva for nistar and not to reveal to the Ohr HaChaim who he was, hiding his identity until the Ohr HaChaim would feel it and understand for himself.
When Rav Gershon arrived he requested permission to hear a derosha from the Ohr haChaim. Permission was granted and he studied in Yeshivas HaNigle for about a week. Afterward, he requested admission to the other Yeshiva for Kabbola.
“Who revealed to you that I have a Yeshiva for nistar?”
He answered that his brother-in-law, the Ba’al Shem, had told him. The Ohr HaChaim did not know him, but he scrutinized Rav Gershon from head to toe and declared him fit and ready to study Kabbola. After studying there for three days, the Ohr HaChaim gave word to prevent him from coming back and Rav Gershon found his way blocked from entry.
When Rav Gershon approached the Rav’s house to find out why he had been banned, the Ohr HaChaim saw him and said, “I am angry at you. Why didn’t you say your brother-in-law was the Ba’al Shem Tov? You just said, ‘Rav Yisrael Ba’al Shem!’ I don’t know any Rav Yisrael Ba’al Shem, but I know who the Ba’al Shem Tov is! I know him from seeing him in the supernal worlds!” and he no longer allowed Rav Gershon access to the Yeshiva, explaining that he needed no other Rebbe or Rav if he already had the Ba’al Shem Tov. (Doresh Tov Tshortkov, Acharon Shel Pesach p. 194)
