"Neither shall he greatly multiply to himself silver and gold"—Deuteronomy 17:17.
A king may not amass personal wealth. He may keep in his personal treasury funds sufficient to pay his servants' and soldiers' wages—but no more than that. And for communal purposes, he may collect as much as he wishes.
The reason for these prohibitions – against accumulating wives, horses and money – is explicitly stated in the Torah: "He may not acquire many horses for himself, so that he will not bring the people back to Egypt in order to acquire many horses... He shall not take many wives for himself, so that his heart shall not turn away [from G‑d], and he shall not acquire much silver and gold for himself."
Because the reasons for these mitzvot are known, many decided to disregard them [claiming that the reasons do not apply to them]—even Solomon, despite his incredible wisdom and knowledge, and despite the fact that he was dubbed "a friend of G‑d" [fell into this trap].
This is a valuable lesson for us all. Were we to know the reasons behind all the mitzvot, we would find reasons to abolish them all. If Solomon made this mistake, certainly the weak-minded general public would the same, saying, "G‑d only commanded us to do this, and forbade us from doing that, because of such and such. We will be meticulous regarding the reason why the mitzvah was given—but will disregard the mitzvah itself." And the entire religion would thus be lost.
Therefore G‑d concealed the reasons behind [many of] the mitzvot, and most of the reasons are beyond the comprehension of the general population.
But there is not one that doesn't have logic and reason. They are all, as the prophet testifies, "the statutes of G‑d are upright; they make the heart rejoice."
And I beseech G‑d for assistance in observing all that He commanded, and distancing all that He forbade.
And this is what we wished to include in this work.
Translator's Note: This is the final mitzvah in the Sefer Hamitzvot.