This sugya focuses on the well-known principle of Lo Ba'Shamayim Hee, which teaches that the Halacha cannot be determined in Shomayim once the Torah was given to Klal Yisroel on Har Sinai. We analyze the parameters of this tenet, and discuss various seeming contradictions in Shas. We discuss the influence of a Bas Kol or Eliyahu Hanavi on a Halachic ruling.