Early in the book of Joshua we are given the rather amazing information that the Israelites ceased practicing circumcision in the wilderness. A whole generation of people were participating in the Tabernacle worship and sacrificial system who had not been circumcised.
Another interesting detail is that there is no sign of the mixed multitude of Egyptians that accompanied Israel out of Egypt into the wilderness.
So what happened? The most obvious solution to me is that they simply got merged into the twelve tribes. After all, there was increasingly little distinction between them as they progressed through the wilderness. Neither were circumcised; and then everyone was circumcised when they entered the Land.
I think that this point goes to show that God was not ‘separating’ Jews (Hebrews) from Gentiles in the same way that many of us often think. Sure, there was a religious separation between covenant and non-covenant, but there was no real racial separation which preclude a Gentile from embracing the Covenant. Gentiles could (And did) ‘join’ up with the ‘Hebrews’. The truth is, MOST of the members of the “tribes” of Abraham were NOT descendent’s of Abraham.
This is one of the reasons I don’t buy the argument floating around that the Torah must be done away with BECAUSE it was used by God to enforce a racial separation that would one day be done away with in Christ.