18 “See that the Kohathite tribal clans are not destroyed from among the Levites.

Read Numbers 4:18 Using Other Translations

Cut ye not off the tribe of the families of the Kohathites from among the Levites:
"Let not the tribe of the clans of the Kohathites be destroyed from among the Levites,
“Do not let the Kohathite clans be destroyed from among the Levites!