We say in our Yom Tov davening:
קדשנו במצותיך
- Sanctify us with your mitzvos. That refers to Pesach, when we received the first mitzvos [such as kiddush ha-chodesh].
וקרבתנו מלכנו לעבודתך
- You brought us close to your service. That is alluding to Shavuos, as it says about Mattan Torah - תעבדון את הא-להים על ההר הזה.
ושמך הגדול והקדוש עלינו קראת
- Your Holy name you called on us. That is Succos. The word סוכה is bi-gimatria 91 which is the name of הוי"ה [26] and א-ד-ני [which equals 65] together. To sit in the Succah is to sit in Hashem's shade.
The arba minim also allude to the four letters of the name הוי"ה as the Mekubalim teach.
Another remez - we sit in the "shade" of the succah. The word for shade is צל. What should we do in the shade? צל! The צ refers to the tzadik. The ל means למד - learn!! A tzadik should learn in the succah and who isn't a tzadik after the high holy days?!