To prove that this verse is speaking about the Lord Jesus coming to the earth to sit upon His throne in the future:
"When the Son of man shall come in his glory, and all the holy angels with him, then shall he sit upon the throne of his glory" (Mt.25:31).
Ok - but I am wondering what this has to do with Israel and a literal physical promised land ...
What the Lord Jesus said there was in answer to His disciple's question, "Tell us, when shall these things be? and what shall be the sign of thy coming, and of the end of the age?" (Mt.24:3).
They asked Him about His "coming" to the earth so when He answered about His coming in glory He was speaking about "coming" to the earth and sitting on His throne.
Since you have no place for that event in your eschatology you must somehow pervert His plain meaning.
That is in the new Heavens and earth and when the New Jerusalem comes down from Heaven. The heavens and earth will be burned up and cease to exist. Jesus is not going to physically rule from this current corrupt and cursed planet. He is going to rule in a new glorious realm. In fact, it already exists. We just cannot see it until that age to come appears before our eyes.
Are you really ignorant of the fact that the Father will give the "throne of David" to the Lord Jesus?:
"He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end" (Lk.1:32,33).
God has already given the throne to Jesus. The Throne was His when He was born. Even the Jews recognized His Kingship and that He is the Son of David.
Here the Lord Jesus speaks of two different thrones so it is evident that there is not just one throne, as you imagine:
"To him that overcometh will I grant to sit with Me in My throne, even as I also overcame, and am set down with My Father in His throne" (Rev.3:21).
If you believe there are two Thrones in Heaven, then why did Hebrews say this:
Hebrews 1:8
But unto the Son he saith, Thy throne, O God, is for ever and ever: a sceptre of righteousness is the sceptre of thy kingdom.
When I look at the references in Rev pertaining the Throne - I see only one - that both Jesus and God sit upon.
Rev 4
2 And immediately I was in the spirit: and, behold, a throne was set in heaven, and one sat on the throne. 3 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald.
8 And the four beasts had each of them six wings about him; and they were full of eyes within: and they rest not day and night, saying, Holy, holy, holy, Lord God Almighty, which was, and is, and is to come. 9 And when those beasts give glory and honour and thanks to him that sat on the throne, who liveth for ever and ever, 10 the four and twenty elders fall down before him that sat on the throne, and worship him that liveth for ever and ever, and cast their crowns before the throne, saying, 11 Thou art worthy, O Lord, to receive glory and honour and power: for thou hast created all things, and for thy pleasure they are and were created.
Rev 7
15 Therefore are they before the throne of God, and serve him day and night in his temple: and he that sitteth on the throne shall dwell among them. 16 They shall hunger no more, neither thirst any more; neither shall the sun light on them, nor any heat. 17 For the Lamb which is in the midst of the throne shall feed them, and shall lead them unto living fountains of waters: and God shall wipe away all tears from their eyes.
Rev 21
5 And he that sat upon the throne said, Behold, I make all things new. And he said unto me, Write: for these words are true and faithful. 6 And he said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely. 7 He that overcometh shall inherit all things; and I will be his God, and he shall be my son.