Each week we say in Havdalla
לַיְּהוּדִים, הָיְתָה אוֹרָה וְשִׂמְחָה, וְשָׂשֹׂן, וִיקָר / layehudim haisa ora v'simcha v'sason v'ikar" -- "'For the Jews there was radiance, and happiness, and joy, and honor' / so may it be for us!"
the Gemara in Megillah teaches that orah refers to Torah, simchah refers to Yom Tov, sasson refers to milah, and yekar refers to tefillin. If so, wonders the Sfas Emes, why didn’t the Megillah express this directly, by saying that the Yidden had Torah, Yom Tov, milah, and tefillin, instead of using codes? Why do we have to infer that orah is Torah, and so on?