49 However, you shall not number the tribe of Levi, nor shall you count their heads among the sons of Israel.
Numbers 1:49 Cross References - LITV
Numbers 2:33
33 But the Levites were not numbered among the sons of Israel, as Jehovah commanded Moses.
Numbers 26:62
62 And those numbered of them, twenty three thousand; all males from a month old and upward. For they were not counted among the sons of Israel, because there was no possession given them among the sons of Israel.