At the beginning of Hilchot Chanukah, the Rambam describes the historical background of the Chag. He shares with us the well-known story of the Chashmonaim capturing the Mikdash and defeating their enemies. Rambam acknowledges that the Chashmonaim assumed the Malchut (kingship) and despite the fact that the Chashmonaim were not from the Davidic dynasty and should not have seized the Malchut, Rambam does not criticize them.
The Ramban, however, commenting in Parshat Vayechi on the Pasuk, לא יסור שבט מיהודה, “the scepter shall never leave Yehuda” (49:10) praises the Chashmonaim for their heroism but is critical of their seizing the Malchut and violating the edict of לא יסור שבט מיהודה. The Ramban also quotes a Sifri commenting on the juxtaposition in Parshat Shoftim of the Pesukim, למען יאריך ימים על ממלכתו הוא ובניו בקרב ישראל, “[Fulfilling the Mitzvot incumbent upon a king will serve] to lengthen the days of his and his sons’ dynasty in Israel” (17:20), and, לא יהיה לכהנים הלויים כל שבט לוי חלק ונחלה עם ישראל, “The Kohanim and the entirety of Shevet Levi shall not have a portion with Bnai Yisrael” (18:1) Sifri comments that Shevet Levi is precluded not only from taking a portion in Eretz Yisrael, but also from accepting the kingship. The phrase למען יאריך ימים על ממלכתו does not apply to Shevet Levi.
The Rav, zt”l, explained the significance of this prohibition. Rambam writes in Hilchot Melachim that although we prefer to bestow the Malchut upon Shevet Yehuda, a king appointed by any Navi from any Shevet is valid. The notable exception is Shevet Levi. Levi is never to occupy the Malchut. This is because every king required a spiritual guide to serve as his מוכיח. During the time of the first Bait Hamikdash each king had a Navi who served as his מוכיח. Shaul had Shmuel, David had Natan, Chizkiyahu had Yeshayahu, and even Yeravam had Achiah Hashiloni. During the second Bait Hamikdash, Nevuah ceased to exist. The spiritual advisors were then the Kohanim and Leviim. Consequently, Shevet Levi could never occupy the Malchut, for no checks and balances could exist if the king and מוכיח merged into the same person. Hence, Ramban is critical of the Chashmonaim. Despite their bravery and heroic actions, they should never have seized the Malchut. It was this merger of Malchut and מוכיח that eventually led to the downfall of the empire.
Every individual today also needs a spiritual guide. On this Yom Tov of Chanukah we should seek any luminary who can pave a Torah way of life for us. By establishing a link with a Torah light we will all be זוכה to the fulfillment of the text expressed at the conclusion of the הנרות הללו prayer as formulated in Masechet Sofrim: כן יעשה הקב"ה נסים ונפלאות לנו ולכל ישראל.