Heidegger's Bible Handbook: Numbers: Its Title
1. The names of the book.
The fourth book of Moses is called Ἀριθμῶν or Numbers, because in it both a number and census of the people of Israel is undertaken by Moses and Aaron: and also all things pertaining to their departures, to the matters conducted in their departures, and to the arrangement for taking possession of the inheritance of the land of Canaan, are reckoned in number. Thus Athanasius in his Synopsi: Ἀριθμῶν συγγραφὴ λέγεται, ἐπειδὰν καὶ τοῦ λαοῦ παντὸς ὁ Ἀριθμὸς τούτῳ περιέχεται, It is called the Book of Numbers, because in it is contained the whole number of the people. Among the Hebrews it is named after the first word וידבר, Vajedabber, and He spake, and also after a more significant word of the first verse, במדבר, in the wilderness, because what things are narrated in the book happened in the wilderness.