On Shabbat Chol Hamoed we read from Parshat Ki Tisa, in the section following “chet ha’egel.” Hashem makes a “Brit” with us, הנה אנכי כורת ברית, and we are warns not to enter into a covenant with the heathens in the land, השמר לך פן תערוכת ברית ליושב הארץ, repeated with… פן תכרות ברית.
The Torah goes on to prohibit manufacturing molten gods, then introduces Passover and Matza. את חג המצות תשמור. שבעת ימים תאכל מצות….
The Gemara (Makot 23a) teaches that he who disgraces the Moadim is equivalent to one who worships idols, as these last 2 psukim are juxtaposed. Maharsha points out the centrality of the Exodus to our holidays, and how to this is central to our belief system, antithetical to Avoda Zara.
Interestingly, Riva”n (we don’t have Rashi past 19b) understands that the Gemara is referring to observing “Chol Hamoed”. May we sanctify Yomtov, as well as eat, act, and dress in the manner that Chol Hamoed deserves.
Shabbat Shalom and Chag Sameach