Numbers 6:8

6:8 All the days of his separation he must be holy to the Lord.

Numbers 16:21

16:21 “Separate yourselves ¹  from among this community, ²  that I may consume them in an instant.”

[16:21]  ¹ tn The verb is הִבָּדְלוּ (hibbadÿlu), the Niphal imperative of בָּדַל (badal). This is the same word that was just used when Moses reminded the Levites that they had been separated from the community to serve the Lord.

[16:21]  ² sn The group of people siding with Korah is meant, and not the entire community of the people of Israel. They are an assembly of rebels, their “community” consisting in their common plot.