26:1 The prophet revealed another song that will be sung "in that day"(the Millennium, cf. ch. 25) by those in Zion.
The New Jerusalem that God will set up will be a place of strength and security for the redeemed (cf. Rev. 21:9-22:5). I believe this will be a literal city with walls and gates, but many interpreters take the description as metaphorical. In that case what Isaiah meant was only that God would provide strength and security for His people.
26:2 Isaiah, writing as a psalmist, called on the porters to open the celestial city gates so the nation that was right with God could enter (cf. Ps. 15:1-5; 24:3-10; 118:19-22). The nation refers to Israel specifically in the context. Faithfulness and loyalty to the Lord will mark Israel then.
26:3 The Lord keeps in true peace the mind-set that consistently trusts in Him (cf. Matt. 6:24; Phil. 4:7; James 1:6-8). Here believers are viewed corporately, but the same truth applies individually (cf. Ps. 112:7-8).
"Stayed upon Jehovah, hearts are fully blest,
finding, as He promised, perfect peace and rest."246
26:4 Isaiah urged everyone to trust in the Lord as a way of life, not just in a saving act of faith, because Yahweh, even Yahweh, is the very essence of what an everlasting rock should be (cf. 17:10; 30:29; 44:8; Exod. 33:21; Deut. 32:4; 1 Sam. 2:2 2 Sam. 22:2, 32; Ps. 18:2; 19:14; 61:2; 1 Cor. 10:4). His presence is an unmoving place of refuge and protection from the elements and from all enemies.247
"The issue of trust is the key to the entire segment beginning at 7:1 and concluding at 39:8. Will Judah commit her security to the nations or to God?"248
26:5 The New Jerusalem is secure because God brought down the city of the world and the proud who inhabited it (cf. 25:12). This is the reason God's people can and should trust in Him.
26:6 The feet of God's afflicted and helpless people will trample the fallen world (cf. Matt. 5:1-12), but it is the Lord alone who will subdue it.
