Source of the authority of Rabbis to "create" mitzvot: Succah 46a
For a Court to Change the Size of threshold quantities for mitzvot/Transgressions: Yoma 80a
For the Rabbis to find a verse and base themselves upon it ["Kera Ashkechu VeDarush"]: Succah 51b
Inability of a court to overturn an earlier court's ruling, unless it is greater in knowledge and number: Megillah 2a
Inability of a Court to overturn a rule of the Men of the Great Assembly: Megillah 2a
Difference between rabbinic and biblical Mitzvot, regarding the assumption that an emissary will carry out his appointed task [Chazakah Shaliach Oseh Shelichuto]: Eruvin 31b-32b
Lo Tasur - The Torah's Prohibition against breaking a Rabbinic Prohibition
