The Megillah vs. The Torah, Or -- The Jews of Sinai vs. the Jews of Shushan

"And they stood beneath the mountain" (Exodus 19:17).

Rabbi Avdimi bar Ḥama bar Ḥasa said: This verse teaches that the Blessed Holy One inverted the mountain above them like a vat, and said to them:

If you accept the Torah, that's good,

and if not, there will be your grave.

Rav Aḥa bar Ya’akov said: From here a substantial piece of knowledge about/objection to the Torah!

Rava said: Even so, they went back and accepted it in the days of Ahashverosh, as it is written:

"The Jews fulfilled and accepted" (Esther 9:27) -- meaning they fulfilled what they had previously accepted.