Bava Metzia 59b says that at the end of the episode of the Oven of Akhnai, Rabbi Eliezer ben Hyrcanus was excommunicated. (Apparently there's a makhloket about whether this was nidui or cherem.) The ...
I remember learning a gemarah (midrash?) that one of the tanaim (possibly R' Chanina [ben Dosa]) said the shem hameforash explicitly. Can you source this story and explain why the shem hameforash was ...