And this is the record of John, when the Jews sent priests and Levites from Jerusalem to ask him, Who art thou?
Note 1 at Joh 1:19: Levites were Jews of the priestly tribe of Levi. However, they were not from the family of Aaron; therefore, they could not be priests. The Lord commanded Moses to separate the tribe of Levi (Levites) to service the tabernacle (Nu 1:47-54). The Lord "hallowed" the whole tribe of Levi unto Himself instead of the firstborn of every family (Nu 3:5-13). In Nu 16, God dealt very severely with some Levites who wanted to overstep their bounds and become priests (Nu 16:8-11 and 31-33).