Numbers is a continuation of Exodus, recording the stay of the Israelites in the wilderness of Sinai until their arrival in Moab. The title of the book is derived from the two numberings of the people recorded here.

Numbers 3

3:38 But those that encamp before the tabernacle toward the east, even before the tabernacle of the congregation eastward, shall be Moses, and Aaron and his sons, keeping the charge of the sanctuary for the charge of the children of Israel; and the stranger that cometh nigh shall be put to death.