“I have a minor Mitzva, whose name is Sukkah [a Sukkot hut]” (Avoda Zarah 3). Why is it called “a minor Sukkah”? It is because there is no shortage of money in it.
We should understand why specifically Sukkah is regarded as having no shortage of money in it, since a Sukkah certainly costs more than other Mitzvot [pl. of Mitzva], such as a Mezuzah [a case affixed on the doorpost containing excerpts from the Torah], for example. According to what is explained in The Zohar, a Sukkah is called “a shadow of faith.” Baal HaSulam interpreted that the word Sukkah comes from the word Sechach [thatch], which covers the mind, since faith is considered specifically above reason.
Hence, in the future, when everyone seeks reward, we should interpret that it pertains to people who are from the descendants of Israel. If they did not engage in Torah and Mitzvot [commandments] for the sake of the Creator, they can ask for reward for their actions, what they intended while they engaged in Torah and Mitzvot, but the Creator pays only those who work for Him (as in the story that was written in the books, about someone who was learning for a cat).
At that time, the Creator tells them, “Observe a minor Mitzva,” namely faith, meaning when you perform Mitzvot, your intention should be Lishma [for Her sake].
In this there is no shortage of money, meaning they do not need to do other works or Mitzvot for the sake of the Creator, but through that same Mitzva that he does and for which he spends money, for the Lo Lishma [not for Her sake]. Because when working for the sake of the Creator, all he needs while doing it is the thought, and thinking does not cost him money, for in any case, he is performing the Mitzva.
However, his intention is for the sake of others. Hence, when he aims for the sake of the Creator, meaning with faith in the Creator, called Sukkah, he has no shortage of money. At that time, through faith in the Creator, it turns out that he works for the sake of the Creator, and then the Creator pays his reward, to all those who work for Him.