Musar על ברכות 14:9

I have pointed out earlier how Nachmanides has severely faulted the Hasmoneans for grabbing the "crown" of Royalty in addition to the "crown" of Priesthood. The Hasmoneans believed that they personified both the "crown" of Royalty and that of the Priesthood, remembering that Tamar, who was not descended from Yehudah but from Shem, became the maternal matriarch of the Davidic Kingdom. Her ancestor Shem (in his capacity of Malki Tzedek), had also combined the "crowns" of both Royalty and Priesthood in his person. The Hasmoneans used this example as their precedent. When they proclaimed Hallel and sang songs and at the same time kindled the oil that bore the stamp of the High Priest they felt that they symbolised the combined virtues of David and that of the High Priest.