Antiquities III Chapter 12,4

SEVERAL LAWS.

4. Now when this settlement of laws seemed to be well over, Moses thought fit at length to take a review of the host, as thinking it proper to settle the affairs of war. So he charged the heads of the tribes, excepting the tribe of Levi, to take an exact account of the number of those that were able to go to war; for as to the Levites, they were holy, and free from all such burdens. Now when the people had been numbered, there were found six hundred thousand that were able to go to war, from twenty to fifty years of age, besides three thousand six hundred and fifty. Instead of Levi, Moses took Manasseh, the son of Joseph, among the heads of tribes; and Ephraim instead of Joseph. It was indeed the desire of Jacob himself to Joseph, that he would give him his sons to be his own by adoption, as I have before related.