Shabbat: Universal to All Mankind or Exclusive to Israel?

Everlasting Sign for Israel:

"It is a sign between me and the children of Israel forever," (Ex. 31:17).

Universal to All Mankind:

"And it shall come to pass, that from one new moon to another, and from one sabbath to another, shall all flesh come to worship before me, saith the Lord," (Isa. 66:23).

Conclusion:

I think one must consider the possibility that Yeshua will rule a universalized Israel in the Messianic Era.