Keeping Shabbos comes right before the Ma'aseh Eigel. The Sefer HaK’sav V’haKabalah says that refraining from work on Shabbos involves going against your Tevah (nature) since a person naturally wants to always do and accomplish and be in charge; and on Shabbos he sits back and lets Hashem run His world. The Malbim says that keeping Shabbos gives you a taste of Olam HaBah. By the Ma'aseh Eigel, it says: וַיָקֻמוּ לְּצַחֵּק and they got up to enjoy themselves and have a good time.
And this is what upset Moshe so much, when he said: קוֹל עַנּוֹת אָנֹכִּי שֹמֵּעַ I hear their rejoicing. Those who have a Geshmak in evil and Ta'avos Olam HaZeh, obviously aren’t having enough enjoyment in a sweet Shabbos and in learning Torah. In Novardok they learned Mussar B'hispa'alus with such a Geshmak, that Ta'avos Olam HaZeh had no place in their lives.
The entire story of Purim starts off with Achashverosh’s tremendous feasts and fake fun, and Klal Yisroel being Nichshal in: שֶנֶּה נוּ מִּסְּעוּדָתוֹ שֶל אוֹתוֹ רָשָע having pleasure from the feast of that Rasha, despite Mordechai begging them not to. The Gr"a says that although Esther started off being: יְּפַת תֹאַר beautiful, but the suffering she went through by being involved with Achashverosh HaRasha turned her into an ugly: יְּרַקְּרֹקֶת sickly green (Chazal), and only her Chen (appeal) made her become queen.
We see what a good Chinuch Mordechai gave her. And just as her ugliness was a result of her hatred of being married to the fake world of a Rasha, so was her unusual beauty a result of how Geshmak it was to be married to Mordechai HaYehudi, the real Yid (Yehudi) who has a life loaded with unreal Simcha.
The whole Megila is a story of tasting the fake fun, Rachmana Litzlan, and Mordechai & Esther pulling them out of their Hevel (emptiness) and giving them the true Simcha. לַיְּהוּדִּ ים הָיְּתָה אוֹרָה וְּשִּמְּחָה וְּשָשן וִּיקָר The Yidden had light, Simcha, Sasson, and glory. Chazal explain that “light” refers to Torah, “Simcha” is Yom Tov, “Sasson” is Bris Mila and “glory” is Tefilin. The S’fas Emes asks: Why doesn’t the Megila state openly: “The Yidden had Torah, Yom Tov, Bris Mila, and Tefilin”?
We can suggest that since the main Yesod of the Megila is: מְּ חִּ יַ ית עַ מָ לֵּ ק the destruction of Amalek, and Amalek are M'zalzel in our Derech; so we show that we have all the Geshmak of Ta'avos Olam HaZeh in the world, only in the proper way. People who learn Torah are indeed full of light, Chochma, and Geshmak. Ask anybody; there is nothing more delicious than a blatt Gemara.
