Idra Rabba (Zohar 3:127b-145a): R. Shimon bar Yohai convenes with nine other scholars, and they gather in the sacred אִדְרָא, or threshing field, where they thresh out secrets.
The Idra Zuta is considered the deepest teachings of the Zohar.
 
Members of the Idra were Rebbe Shimon bar Yochi, Rabbi Eliezer his son, Rabbi Abba, Rabbi Yehuda, Rabbi Yossi bar Yaakov, Rabbi Yitzchak, Rabbi Chezkiyah bar Rav, Rabbi Chiyya, Rabbi Yossi and Rabbi Yisa.
Rabbi Yossi bar Yaakov, Rabbi Chezkiyah bar Rav and Rabbi Yisa passed away during the Idra.