to the kohanim who were genealogically registered by their ancestral houses, as well as to the Levites 20 years old and upward, according to their duties and their divisions.
The Levites are to camp around the Tabernacle of the Testimony, so that there will be no wrath unleashed on the community of Bnei-Yisrael. So the Levites are to maintain care of the Tabernacle of the Testimony.
Fight the good fight of faith! Take hold of the eternal life—you were called to it, and you made the good confession for it in the presence of many witnesses.