Numbers 4:20

20 but the descendants of K'hat are not to go in and look at the holy things as they are being covered; if they do, they will die."

Numbers 4:20 In-Context

18 "Do not cut off the clan of K'hat from among the L'vi'im;
19 rather, do this for them, so that they will live and not die: when they approach the especially holy things, Aharon and his sons are to go in -and you are to assign each one his task;
20 but the descendants of K'hat are not to go in and look at the holy things as they are being covered; if they do, they will die."
21 ADONAI said to Moshe,
22 "Take a census of the descendants of Gershon also, by clans and families;
Complete Jewish Bible Copyright 1998 by David H. Stern. Published by Jewish New Testament Publications, Inc. All rights reserved. Used by permission.