דברי הימים ב, פרק כ״ט, פסוק כ״ו

Preparation for the musical service in the Temple involved a careful arrangement of its participants. The Levites and the Priests took up their positions, ready to fulfill their specific roles. The Levites stood holding the musical instruments originally established by King David. Right beside them stood the Priests, who were tasked with holding the trumpets.

This clear division of musical duties, with the Priests on the trumpets and the Levites playing the remaining instruments, traces directly back to a command in the Torah. It is based on the explicit instruction that the sons of Aaron, the Priests, are the ones designated to sound the trumpets [רש״י].