"Therefore they shall come and sing in the height of Zion." Jeremiah 31:12
Until the redeemed know something of the efficacy of atoning blood and have their consciences purged from guilt and filth by its application, they cannot come and sing in the height of Zion. But when they are redeemed from the hand of him who is stronger than they; when atoning blood is applied to their consciences to purge away guilt and filth; when Christ is revealed and made experimentally known; when his gospel in the hands of the Spirit becomes a word of power, and a view of the King in his beauty is granted to the believing heart, then, drawn by the cords of love and the bands of a man, they come to Zion, where the King sits enthroned in glory.
It is called "the height of Zion," not only because Zion was high literally, but because the Lord of life and glory is exalted to the highest place of dignity and power. God's ancient promise was, "Behold, my servant shall be exalted and extolled, and be very high" (Isaiah 52:13); and the Apostle says, "therefore God also has highly exalted him, and given him a name which is above every name" (Phil. 2:9); and again, "Far above all principality, and power, and might, and dominion, and every name that is named, not only in this world, but also in that which is to come" (Eph. 1:21).
But why do they come? It is to commune with him, to worship him in the beauty of holiness, to get words from his lips, smiles from his face, touches from his hand, and whispers from his lips. And when he is graciously pleased to speak a word to them as Prince of peace, to reveal himself to their souls in the glory of his divine Person as God-man, and to shed abroad his love in their hearts, then they can sing, and in them is the promise fulfilled, "They shall come and sing in the height of Zion."