Levitical Services in the Mikdash
Requires Beit HaMikdash
BaMidbar 18:23 The Levi[im] himself shall perform the service of the Tent of Meeting, and they shall bear their iniquity, an eternal decree for your generations; and among the Benei Yisrael they shall have no inheritance.
The Leviim are commanded that they alone are to perform certain services in the Temple, such as the closing of the gates, and the chanting during the offering of the sacrifices [offered on behalf of the whole community of Yisrael].1
The Sifre says:
"I might suppose that [a Levi] could choose whether to perform the service or not; Scripture therefore says, "The Leviim alone shall do the service" that is to say, they must do it willy-nilly. It is thus a duty, the performance of which is compulsory."
Then nature of the service of the Leviim is explained in many places in Tamid and Middot; and in the 2nd chapter of
Arakin it is explained that only the Leviim were to chant [in the Temple]. (Arakin 11a)This Mitzvah appears again in another form:
"He [i.e. the Levi] shall minister in the name of Hashem his G-d, as all his brethren the Leviim do" (Devarim 18:7) on which the second chapter of Arakin says: "What is ministering in the name of Hashem? It means chanting." (Arakin 11a)All the Leviim in Yisrael were thus divided into two groups - those that attended only to the gates of the Temple, and those that performed the chanting at the services. It was forbidden for a Leviim of one group to do the work generally assigned to one of the other group
(Arakin 11b).The young Levi was not permitted to do any service in the Temple until he had gone through a 5 year period of initiation or preparation
(Mishneh Torah, Avodah, Hilchot Kle Ha-Mikdash 3, 7).Much attention was devoted by Jewish law to the chanting of the Leviim in the Temple. The Levi whose voice had lost its vigor or its sweetness was disqualified for this service. While the actual chanting was the duty of the Leviim themselves, the accompaniment on musical instruments might be done also by Kohanim and dignitaries of Yisrael
(Arakin 10a)."There were never less than two trumpets, and their number could be increased without end; there were never less than nine lyres, and their number would be increased without end; but of cymbals there was but one, etc. There were never less than twelve Leviim standing on the Platform, and their number could be increased without end. None [of the Leviim] that were not of age could enter the Temple Court to take part in the service, save only when the Leviim stood up to sing; and they did not join in the singing with harp and lyre, but with the mouth alone, to add spice to the music" (ibid., 13b)
1. I.e. the daily Burnt-offerings, the various Additional Offerings, and the Peace-offerings of the community on the Festival of Shevuot