Numbers 26:64

But among these there was not a man of them whom Moses and Aaron the priest numbered..... About thirty eight years before this time: this, as Aben Ezra observes, respects the numbering of the Israelites, not of the Levites; for there were some of the tribe of Levi numbered then who were living, as Eleazar, and very probably Ithamar, and perhaps some few more, though it may be Eleazar, being now a numberer, was not reckoned among the numbered:

when they numbered the children of Israel in the wilderness of Sinai; see Numbers 1:1 for as there were none of the tribe of Levi among the spies, there might be but few of them among the murmurers.