Tradition has it that this is the Beit Midrash of Rebbi Shimon Bar Yochai. The Talmud tells us in several places that Rebbi Shimon Bar Yochai set up a Beit Midrash in Tekoa after he left the cave (in which he and his son Rebbi Eliezer had to hid from the Romans for 13 years see Shabbat 33b) and that Rebbi Yehuda HaNassi learned by him. The Talmud (Menachot 85b) mentions the Biblical story of Yoav sending for a wise woman in Tekoa, and concludes that the Tekoa mentioned in this verse is not referring to the Tekoa in Yehuda, but to Tekoa located in the land of Asher. The Talmud then proceeds to tell a story of a man who was sent by his village to buy oil and ended up in Gush Chalav just north of Meron. The Tosefta Shvi’it (7:12) mentions Tekoa in the same region as Gush Chalav. The Yerushalmi (Shvi’it 26a 9:2) mentions the same statement as the aforementioned Tosefta, but inserts Meron instead of Tekoa. So it was most likely from this very door (or at least the site of the door, as the synagogue may post date Rebbi Shimon) that Rebbi Shimon and his students saw a former student return from a very successful business trip to Rome. The student had made a fortune. Rebbi Shimon noticed that some of his students were also contemplating leaving full time Torah learning to seek out their fortune as well . He thereupon called out “Valley, Valley , I command that you fill up with gold coins”, whereupon the entire valley suddenly sparkled with gold coins. He now turned to his students and told them that they could take all the gold they wanted to. “But remember” he warned them. “It will all be deducted from your share in the world to come.” Not a single student moved from his place.