If in context God makes a promise to geographical, physical, national Israel, then that's what he refers to. God promised Abraham a natural descendancy, a people biologically descended from him who will populate and comprise Israel, a nation located in old Canaan. This promise has never been taken back. On the contrary, all through the Scriptures it has been confirmed. Virtually every prophecy in the OT that has to do with literal Israel has in the back of its mind the eternal nature of these promises, that these things will be fulfilled in eternity.
Some believe, as I do, that Israel must be physically reconstituted before the coming of the New Earth, where no sin will dwell. Sinful mankind and sinful Israel must complete their destiny in the age of human sin before the eternal age of the earth where no sin will be allowed any longer. This may take place at Christ's Coming, as Paul seemed to suggest in Rom 11. In that case, if you're a Premillennialist, you would view the fulfillment of Israel's destiny in the Millennial Age, along with other Christian nations who will comprise God's Kingdom on earth.