וּלְקַחְתֶּ֨ם לָכֶ֜ם בַּיּ֣וֹם הָרִאשׁ֗וֹן פְּרִ֨י עֵ֤ץ הָדָר֙ כַּפֹּ֣ת תְּמָרִ֔ים וַעֲנַ֥ף עֵץ־עָבֹ֖ת וְעַרְבֵי־נָ֑חַל וּשְׂמַחְתֶּ֗ם לִפְנֵ֛י יְהוָ֥ה אֱלֹהֵיכֶ֖ם שִׁבְעַ֥ת יָמִֽים׃ -- ויקרא כ"ג, 40
And take to yourselves on the first day [of Sukkoth] fruit of a majestic tree [or: majestic fruit of a tree], hands [i.e., fronds] of palms, and a branch of a leafy tree and of brook willows, and rejoice before HaShem your God seven days. -- Leviticus 23:40
When I read this commandment, I imagine a joyful folk festival: men, women, and children going down to the brook in a cheerful throng, gathering up different kinds of plants, and waving them happily before the Lord. It's spontaneous, free, colorful, and pretty devoid of ritual. Could be a nice time for a picnic; and certainly there are lots of children running around, laughing, shouting.
The rabbanim interpret this verse differently. An entire tractate of the Talmud forms the basis for their notions regarding the proper laws of Sukkot: the permitted size, shape, and materials of a sukkah; how many meals to eat during the week; the right size for the palm fronds; which kind of fruit-tree is "majestic" (hadar); what kind of points the lulav and etrog have to have to be 'kosher'; etc., etc. Since Mishnaic times many volumes of additional commentary and pronouncements have further defined the rabbinic interpretation of Sukkot. With regard to the verse cited above, the rabbinic regulations specify when the four species (arba'at ha-minim) may be waved; what prayers must be said before, during, and after waving; the precise manner in which they must be waved; the proper technique for taking all four together; and on and on. In other words, the rabbinic observance of this commandment is as ritualized as can be.
I believe in a much, much freer observance of God's commands, based on the spirit of the Torah itself. The rabbis insist on a standardized, controlled, sanctioned, ritualized observance of their massively expanded interpretation of Torah. Which of us is correct?