The Targum Jonathan on (Deuteronomy 17) puts hard numbers on royal power. The Hebrew says the king shall not "multiply horses" or "multiply wives." But how many is too many? The Targum answers with precision: no more than two horses, and no more than eighteen wives.
The horse limit comes with a specific reason. The king may have only two, "lest his princes ride upon them, and become proud, neglect the words of the law, and commit the sin of the captivity of Mizraim." Excess horses lead to pride, which leads to Torah neglect, which leads to Egypt. The Targum draws a straight line from cavalry to spiritual collapse. And it ends with a devastating callback: "By that way ye shall return no more." The road to Egypt runs through the royal stable.
Eighteen wives is a number that directly references King David, who according to rabbinic tradition had exactly eighteen wives. The Targum sets David's practice as the maximum legal limit. Solomon, who had hundreds, exceeded the law—and the Targum adds that the danger is not merely personal but political: too many wives "pervert his heart." Silver and gold are also limited, "lest his heart be greatly lifted up, and he rebel against the God of heaven." The Targum uses "God of heaven" rather than "the Lord your God"—a more imperial-sounding title appropriate for addressing a king.
The legal system described earlier in the chapter creates a detailed judicial hierarchy. When a case is too difficult for local courts—involving "unclean and clean blood, cases of life or of money, or between a plague of leprosy or of the scall"—the case goes up to the central court at the Temple. The Targum calls the local courts "your beth din" and the central authority "the priests of the tribe of Levi and the judge who will be in those days."
Defying the court's ruling carries the death penalty. "The man who will act with presumption, and not obey the judge or the priest"—the Targum says this is necessary so that "all the people will hear, and be afraid, and not do wickedly again." Judicial authority is enforced through public deterrence.
The chapter ends with the king's primary obligation. He must keep a Torah scroll "at his side" and "read it all the days of his life." The elders must write "the section of this law" for him specifically. The Targum envisions a king defined not by his army or his wealth but by his daily reading of the Torah—a monarch whose power is bounded by the book he carries.