The old Jerusalem will also be an inheritance. The Lord is speaking to the branch of the House of Israel in the New World. To them he has given a land of inheritance, which he reiterated in verse 14. The establishment of the New Jerusalem is an indication that the Lord will keep his promise, and that this land will continue to be an inheritance. Likewise, a land was given to the House of Israel in the Old World as an inheritance, and the Lord announces that he fully intends to keep that promise as well. There are these two branches to whom promises have been made concerning the land of their inheritance. The Lord will fulfill those promises on the two different continents. The uniting and gathering of the House of Israel will not be completely physical, but will be spiritual, with the physical gathering represented by the two Jerusalems.