To which author does "BaMidbar 11," which we restored in its proper place, before Parshat Yitro, belong?
Parshat Yitro belongs to E, and rightly so. Only E could write that Yitro came to Har HaElohim, and there are many instances of "Elohim" in this Parasha. Yitro says: "For this matter is too hard for you, you will not be able to do it alone," and he suggests that Moshe appoint leaders of thousands, leaders of hundreds, leaders of fifties, and leaders of tens.
On the other hand, in "BaMidbar 11" it says: "Gather to Me seventy men from the elders of Israel" and "I will increase some of the spirit that is upon you and place it upon them, and they shall bear the burden of the people with you, and you shall not bear it alone." See, the problem has been solved already, and much more spiritually!
Therefore, in my opinion, "BaMidbar 11" must be attributed to J. Then, both E and J address, successively, the same problem: Moshe cannot do it alone. Both indicate a solution to the problem. In E, it says that the original suggestion was from Yitro, and J claims that HaShem came up with a solution, the Sanhedrin. Both solutions are mentioned because both have merits.
And the implication is that the number 600,000 for the initial size of Israel, is J's number.
