What is the mountain of the Lord’s house?
Patrick Fairbairn was the author of “Prophecy Viewed in respect to its Distinctive Nature; its Special Function and Proper Interpretation,” a book which went through several editions in the nineteenth century.  A review of Fairbairn’s book published in The Quarterly Journal of Prophecy challenged his spiritual or figurative approach to the interpretation of prophecy.
The reviewer compared his own interpretation of Isaiah 2:3 with Fairbairn’s. He wrote: 
There is another passage on which Dr Fairbairn comments, which affords so good an example of the difference between the figurative and the symbolical, that we cannot forbear to notice it, even at the risk of somewhat unduly extending this article. Isaiah says, “It shall come to pass that the mountain of the Lord’s house shall be established on the top of the mountains, and shall be exalted above the hills, and all nations shall flow into it.” Dr Fairbairn interprets this passage symbolically. The mountain of the Lord’s house is to be taken, in a moral sense, of the divine kingdom; the other mountains mentioned in connexion with it, over which it was to be exalted, are the rival powers and monarchies. We deny that there is any warrant whatever for interpreting this chapter as a symbolical prophecy. It is indeed true, that a mountain is occasionally used as an emblem, but this does not prove that wherever a mountain is spoken of, it is to be taken in this emblematic manner. The passage, too, in Ezekiel, on which Dr Fairbairn relies, seems to be altogether beside his purpose. The “mountain of the height of Israel” appears to be one thing; and the “mountain of the Lord’s house” another; and this latter phrase seems to point so distinctly to the literal Mount Moriah, that it would require much stronger reasons than any that have yet been adduced to convince us of the contrary. We interpret it, therefore, as a historical fact, conveyed in language heightened by figurative expressions. It is not an elevation of Mount Zion above other hills by some remarkable physical change that we look for. Those who have done so have erred in the opposite direction from Dr Fairbairn, but the source of error is the same. They did not distinguish between the figurative and the symbolical; and because they were not prepared to allow that all prophecy is symbolical, they committed the mistake of attempting to deal with it all as unfigurative. But our interpretation will put our views in a very plain light. In the 68th Psalm David celebrates the excellency and dignity of Mount Zion, to which he had brought the ark of the covenant. “The hill of God,” he says, “is as the hill of Bashan; an high hill, as the hill of Bashan. Why leap ye, ye high hills; this is the hill which God desireth to dwell in; yea, the Lord will dwell in it for ever.” We take this passage to be the exact counterpart of the prophecy under consideration. David speaks of the past or present, Isaiah of the future; but the subject is the same, and the same manner of interpretation will lead to the true meaning of each. It is not the physical altitude of Zion that David commends, nor does any one suppose that the hills had really leaped: but he asserts that there is not anywhere a hill so high that can compare for glory with Zion: no, not the snowy top of Hermon, the hill of Bashan. He represents the hills as envious; that one whose height was little compared with theirs should spoil them of their glory, and then points out the true cause of its pre-eminence—God had chosen it for His habitation. In like manner, Isaiah, looking into the future, sees the dawn of a day when Mount Zion shall be so glorious that no earthly mountain can be named along with it, and when there shall not be a nation whom the radiance of that glory shall not attract. But, it may be said, this is a figurative and not a literal interpretation for which you contend. True, Isaiah as well as David uses figurative language; but the interpretation is literal in this sense, that it is not symbolical. Zion is still Zion, the mountain of the house of the Lord.
The reviewer claimed that the “mountain of the height of Israel” of Ezekiel 17:22 and the “mountain of the Lord’s house” in Isaiah 2:3 are separate, and distinct; mount Zion is the literal hill in the earthly Jerusalem, or perhaps the reviewer means the nation of Israel after the flesh. But that seems contrary to the thought in Hebrews 12:22-23: “But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels, To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect, And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel.”
Here, in the New Testament, mount Zion, and Jerusalem are raised up to heaven, and all Christians have come to it. Mount Zion represented the temple, and Jesus identified himself with the temple. He was raised up to heaven after his resurrection, and so fulfilled Isaiah’s prophecy.
This supports Fairbairn’s argument that the elevation of mount Zion was spiritual in nature. He dismissed the notion that the prophecy refers to a physical elevation of the literal place by means of earth movements. Fairbairn wrote: 
We shall refer to another prediction of Isaiah, found at the commencement of the second chapter, where, in speaking of the glory of the latter days, he says, “It shall come to pass that the mountain of the Lord’s house shall be established on the top of the mountains, and shall be exalted above the hills; and all nations shall flow unto it.” It is spoken absolutely, and, therefore, if taken as an historical delineation, must be regarded as importing that the little elevation of the temple mount shall be projected upwards, and made to overtop in height the loftiest of the Himmalayas—and that, too, for the purpose of increasing its attraction as a centre of religious intercourse to the world, and drawing men in crowds toward it from the most distant regions. What a mighty revolution—what an inversion even of the natural state of things, this would imply, it is needless to point out. Yet the interpretation now given has often been adopted, as conveying the real meaning of the prophecy, if not to the extent of making Zion absolutely the loftiest summit on the earth’s surface, at least to the extent of its elevation above all the hills in that region of the earth. So common, indeed, had this view of the literal elevation of Mount Zion in the latter days, become in the time of Edward Irving, that we find him excusing himself from not implicitly adopting it. He expresses, indeed, his belief that there would be “some remarkable geographical changes on the face of the earth, and especially in the Holy Land”—so that he was “far from slighting the more literal interpretation of the passage;” yet, withal, “he inclines to think that the glory of Zion, in the eye of the prophet, standeth rather in this,—that it shall acquire such a celebrity in those days as shall bring low the most noted of the mountains of the earth, and the eyes of all men upon it, being the centre of the worship of the whole world.” Even the better sort of Jewish rabbies read with a less fleshly eye the meaning of the prophet. “It does not mean,” says Kimchi, “that the mountain shall be raised in bulk, but that the nations shall exalt and honour it, and shall go there to worship the Lord.” But we have a surer interpreter here than either Jewish rabbies or Christian divines. For the prophet Ezekiel, evidently referring to this prediction of Isaiah, connects it with circumstances which oblige us to understand the relative elevation of the sacred mount, as of a spiritual, not of a natural, kind, and as verified in what already has been, not in what is yet to be. Representing the seed of David as the subject of promise, under the image of a twig of a lofty cedar, and contrasting what the Lord would do to this, with what was to become of the twig cropped from the same cedar by the king of Babylon, the prophet says in the name of the Lord, “I also will take of the highest branch of the high cedar, and will set it; I will crop off from the top of his young twigs a tender one, and will plant it upon an high mountain and eminent: in the mountain of the height of Israel will I plant it; and it shall bring forth boughs, and bear fruit, and be a goodly cedar; and under it shall dwell all fowl of every wing; in the shadow of the branches thereof shall they dwell” (chap. xvii. 22, 23). There cannot be the smallest possible doubt that the young and tender twig here mentioned represents Jesus of Nazareth, the branch, as he is elsewhere called, out of the roots of Jesse, and represents Him in His first appearance among men, when he came in the low condition of a servant, to lay through suffering and blood the foundation of His everlasting kingdom. For, it is of the planting of the twig that the prophet speaks, and of its original littleness when so planted, as compared with its future growth, and ultimate peerless elevation. Yet even of those very beginnings of the Messiah’s work and kingdom, it is said, that they were to take place on “an high mountain and eminent,” on “the mountain of the height (the mountain-height) of Israel.” So that, as seen in prophetic vision, the elevation had already taken place when Christ appeared in the flesh, the little hill of Zion had even then become an enormous mountain; in other words, it was not the natural, but the spiritual, aspect of things which was present to the eye of the prophets, when they made use of such designations. All Israel was in this view a height, because distinguished and set up above the nations by its sacred privileges; [See Ezekiel xxxiv. 14, and the note there in my Commentary.] Mount Zion was the loftiest elevation in that height, because there was the seat and centre of what rendered Israel pre-eminent among the nations; and when seen as the place where God, manifest in the flesh, was to accomplish the great redemption,. and unspeakably enhance the good, by turning what before was shadow into substance, then its moral grandeur indeed appeared transcendent, and all that might be called great and lofty in the world shrank into littleness as compared with it. Here now was the world’s centre—the glory that eclipsed every other.
If it were necessary to our argument, and would not lead us too far from our present purpose, we might strengthen the ground of this interpretation, by showing how commonly in prophetic language powers or kingdoms, as such, are spoken of under the image of mountains—mountains varying in height or stability according to the character and position of the kingdoms themselves. We merely refer to the fact (giving a few instances in [Appendix D]), and shall find occasion when we come to treat of the positive aspect of the subject, to shew the essential connection of such a style of representation with the usual form in which prophetic insight was given. But from the examples already adduced, it is manifest, that if we would not render prophecy in some parts utterly fantastical, and in others plainly inconsistent and contradictory, we need other rules to guide our interpretations, than that of a strict adherence to historical simplicity. Prophecy cannot be always read merely as history antedated. And the absolute impossibility of making out, on such a principle, a prophetic harmony, or, to state it positively, the inevitable confusion and discord it would introduce into the prophetic record, may be further seen by a comparison of the diverse and, historically considered, antithetical representations, that are given of the religious changes that were to come in with the gospel dispensation. Sometimes this appears as a revival and perfecting of the old, and sometimes, again, as the entire supplanting of it by something higher and better. Thus Isaiah, in certain places, speaks of the future glory as consisting in the full re-establishment of the old things, the erection of the temple in surpassing magnificence, the rigorous enforcement of its ritual, and the vieing of all nations with each other to frequent its courts and celebrate its sendees (chap. lx.; lvi. 7, 8; lxvi. 21-23); while, in other places, he pours contempt upon the old, as not worthy to be mentioned, treats the erection of a material temple, like that which formerly existed, as a thing no longer to be thought of, and holds out promises of blessing, which imply the abolition of the ordinances introduced by Moses (chap. lxv. 17; lxvi. 1-3; lvi. 3-5). In like manner, Jeremiah, setting forth, at chap. iii. 16, the superiority of the latter days, affirms that the time was coming when they should no more remember or speak of the ark of the covenant, nor make such a thing—meaning, that the peculiar sacredness and glory belonging to it should then be more widely diffused, not confined to so limited a spot. In another place (chap. xxxi. 31), he tells us of the supplanting of the old covenant entirely by a new one, founded on better promises; and yet, passages again occur in which he depicts the full and perfect re-establishment of the ancient order of things, as the glory of those latter days (chap. xxx. 18-22; xxxiii. 15-22). To mention no more, Ezekiel’s last vision of the brighter future presents all under the aspect of a re-edified temple, perfect in its structure and arrangements; while, in St John’s last vision, it takes the form of a holy city, complete in its proportions, and composed of the most precious materials, but having in it no temple. There is a principle, we may be well assured, which is quite sufficient to harmonise these different representations, and render them perfectly consistent with one another; but no skill or sophistry can ever persuade simple and unprejudiced men, that such a harmonising principle is to be found in reading the whole as one would read history—taking all as matter-of-fact descriptions of gospel times, or the millennial age. On that principle, the contradiction is necessarily real, and we have no alternative, according to it, but that of holding by one portion of the prophetic future, and letting go another.
While Fairbairn thought mountains were symbols of kingdoms, the Scriptures support the idea that they represent the blessings, and covenants, and promises of God. In Genesis 49:26, when Jacob blessed Joseph, he said the blessings that he had received “have prevailed above the blessings of my progenitors unto the utmost bound of the everlasting hills.” They were high, and lofty, as they were spiritual in nature, and also durable, or eternal, like the “everlasting hills.” This was also pointed out by H. A. C. Hävernick in 1843.  W. J. Schröder wrote of his interpretation of the mountains of Israel in Ezekiel 36: 
Havernick refers to Gen. xlix. 26 (Deut. xxxiii. 15), according to which the mountains are held to stand in relation to the promises of Israel as imperishable memorials of the patriarch’s blessing.
The kingdom of God is one of these promises, and so it is represented by a mountain.
The Psalmist sometimes refers to mountains and hills as “leaping,” and becoming airborne. “The mountains skipped like rams, and the little hills like lambs.” [Psalm 114:4] The reason, I suggest, is that the physical land of Canaan in the promise to Abraham has a spiritual and heavenly significance; “now they desire a better country, that is, an heavenly: wherefore God is not ashamed to be called their God: for he hath prepared for them a city.” [Hebrews 11:16]
1. Patrick Fairbairn. Prophecy viewed in respect to its distinctive nature, its special function, and proper interpretation. T. and T. Clark, 1856.
2. Fairbairn on Prophecy. The Quarterly Journal of Prophecy. October 1857. pp. 283-284
4. Heinrich Andreas Christoph Hävernick. Commentar über den Propheten Ezechiel. Erlangen: C. Heyder. 1843. p. 569.
5. Wilhelm Julius Schröder. The Book of the Prophet Ezekiel; tr. by Patrick Fairbairn, William Findlay.
A commentary on the Holy Scriptures: critical, doctrinal, and homiletical, Volume 13. T. & T. Clark, 1876. p. 338.