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 1

1:18 And they assembled all the congregation together on the first day of the second month, and they declared their pedigrees after their families, by the house of their fathers, according to the number of the names, from twenty years old and upward, by their polls.