Numbers 13:2
2“Send out for yourself men to spy out the land of Canaan which I am giving to the Israelites. From each of their fathers’ tribes send one man1 who is a leader among them.”
Translation Notes
1God explicitly demands that one man from each tribe be sent but no one is sent from Levi. Instead, we find that Ephraim and Manasseh each have their own spy. The same phenomenon can be seen in Numbers 1:14-15. This supports the idea that the tribal scheme that includes Joseph and Levi is a later addition, whereas Ephraim and Manasseh belong to the original system. See The Valediction of Moses by Idan Dershowitz .