The magnificent and stately language used by Isaiah in proclaiming this great event of prophecy, sets it apart, making more bright and beautiful, the exalted and majestic picture he here presents. "How beautiful upon the mountains" expresses his jubilation as Isaiah proclaims the coming of Him, who is King. Not any king, but the King of kings. The term mountains, or mountain is used throughout the Scriptures, and usually means, when not referring to a particular mountain, the glory, or the power, or the Temple of God. The whole earth is God's Temple; its Holy of Holies is in our hearts. It is that place where we bring our prayers, and our praise, and our offerings of homage to Him. It is a temple, not made with hands. It is a "mighty fortress of our God," whose parapets shine with the burnished armour of His servants.
"Who shall ascend into the mountain of the Lord and who shall stand in His holy place? He that hath clean hands, and a pure heart; who hath not taken My name in vain, and hath not sworn deceitfully. He shall receive a blessing from the Lord, and righteousness from the God of his salvation. Such is the generation of them that seek Thee; that seek Thy presence, O God of Jacob." (Ps. 24; Hebrew translation)
"And many nations shall come, and say, Come, and let us go up to the mountain of the Lord, and to the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for the law shall go forth of Zion, and the word of the Lord from Jerusalem." (Isa. 2:2-3)
The words of the Psalmist find fulfillment here: "Honor and majesty are before him: strength and beauty are in his sanctuary." (Ps. 96:6)
As Jerusalem was centered with mountains round about, the Jews, conscious of the mighty defense these mountains afforded their beloved city, making it a citadel, understood the words of the prophet. The imagery created by Isaiah's lofty comparison appealed to the subtle and discerning minds of those who had waited the coming of Him of whom the prophets had long foretold. He was their King, and to them, a Messenger of Salvation, their Rock and their Redeemer. He, they had been told for ages, would lead them into battle and would bring them peace through victory over their enemies. Jerusalem would be enthroned above all the nations of the earth. Their praise of Him was bounded only by their hopes in Him, and by the vision of His glorious appearing which Isaiah announced anew.
Thy God reigneth. This is the grand and final message their King proclaims. All the others are subordinated. Peace, good tidings of man's Redemption are published by Him whom they see approaching on the distant mountains. They watch Him as He draws nearer; His feet are like stars; His raiment, new, like the dawn of day; His voice is like thunder, the reverberations of which shake the earth. He declares His message, "Thy God reigneth." Not, "Thy God will reign," or "He will be King," but "He is King," now and forever. Yesterday, today, and tomorrow, He is the same; our King, our Deliverer, our All. They see the King, they hear His voice. "Peace, God's most precious gift to man," is now declared to be his portion. The Jews remembered the words of the Psalmist, "The Lord will give strength unto His people; the Lord will bless His people with peace." (Ps. 29:11)