Why can't it be the other way around, that I'm sorry for going beyond what you intended?
The fact is as Tal said a Gentile can be circumcised and there is no law against it. The debate is if it's necessary or not for a Gentile to become an Israelite, 'as a native born' so they may partake fully in the Passover.
I am not exactly sure what all you mean in the above Marc. My thoughts on circumcision, are always connected to the priesthood, in the idea of full participation of the promises concerning Abraham's seed. Which is an inheritance. You had to have citizenship to inherit the land.
So yes I believe it was/is necessary to be of a tribe for full participation in the covenant promises. Passover, unleavened bread etc. are memorials to the fulfillment of the Abrahamic promises made in Genesis 15. The priests ministered for the twelve tribes in memorial. They bore thier iniquity etc. The priests vestments only bore the names of the twelve. That is why Gentiles received tribal affiliation upon circumcision. To have a name bore by the order of Aaron. It is just my opinion that the circumcision cannot be separated from this priestly service.
25:7 Onyx stones, and stones to be set
in the ephod, and in the breastplate.
Ex 28:9 And thou shalt take two onyx stones, and grave on them
the names of the children of Israel:
Ex 28:11 With the work of an engraver in stone, like the engravings of a signet, shalt thou engrave the two stones with
the names of the children of Israel: thou shalt make them to be set in ouches of gold.
Ex 28:12 And thou shalt put the two stones upon the shoulders of the ephod for
stones of memorial unto the children of Israel: and
Aaron shall bear their names before the LORD upon his two shoulders for a memorial.
Ex 28:21 And the stones shall be with the
names of the children of Israel, twelve, according to their names, like the engravings of a signet;
every one with his name shall they be according to the
twelve tribes.
Ex 39:7 And he put them on the shoulders of the ephod, that they should be
stones for a memorial to the children of Israel; as the LORD commanded Moses.
I have a question....What was the Memorial/s that the high priest bore on his shoulders ( of Ephod) and his heart (breastplate of Judgment)?