John Gill Commentary Numbers 19:14

"This is the law when a man dieth in a tent: every one that cometh into the tent, and every one that is in the tent, shall be unclean seven days." — Numbers 19:14 (ASV)

This is the law when a man dieth in a tent
A tent is only mentioned, because the Israelites now dwelt in tents, as Aben Ezra remarks; otherwise the law holds equally good of an house as of a tent:

all that come into the tent, and all that is in the tent, shall be
unclean seven days ;
the meaning of which is, that all persons that come into a tent or house where a dead body is are equally unclean as those that were in it when it died; and the same is to be supposed of all vessels brought into it, as well as those that are in it, that is, open ones, as appears by what follows.