עזרא, פרק ב׳, פסוק מ״א

The return to Jerusalem required reorganizing the people according to their traditional roles in the Temple. A key part of this restoration involved the singers, who were Levites specifically appointed to provide song and music for the services. At this moment, the group of singers consisted entirely of the descendants of the Asaph family [רש״י, שטיינזלץ].

This strict division of Levite duties applied to other essential roles as well. Just like the singers, the gatekeepers mentioned nearby were also Levites. Instead of singing, their dedicated responsibility was to stand watch and protect the entrances to the Temple [רש״י].