1 For Zion's sake will I not hold my peace, and for Jerusalem's sake I will not rest, until the righteousness thereof go forth as brightness, and the salvation thereof as a lamp that burns.
Isaiah says he will not shut up until God's glory is seen by all.
2 And the Gentiles shall see thy righteousness, and all kings thy glory: and thou shall be called by a new name, which the mouth of the Lord shall name.
He will speak until everyone sees and acknowledges what a righteous nation looks like.
3 Thou shall also be a crown of glory in the hand of the Lord, and a royal diadem in the hand of thy God.
God's people are His ultimate beauty.
4 Thou shall no more be termed Forsaken; neither shall thy land any more be termed Desolate: but thou shall be called Hephzibah, and thy land Beulah: for the Lord delights in thee, and thy land shall be married.
Hephzibah means “My delight is in her” while Beulah means “Married.”
In the pre-captivity prophecies, God divorced Israel/Judah and said they would by a synonym for “desolate and destroyed” to their neighbors.
Here God promises that will change; He will restore them. They do have hope.
5 For as a young man marries a virgin, so shall thy sons marry thee: and as the bridegroom rejoices over the bride, so shall thy God rejoice over thee.
God desires to have a people He can love with abandon.
6 I have set watchmen upon thy walls, O Jerusalem, which shall never hold their peace day nor night: ye that make mention of the Lord, keep not silence,
I think the watchmen, while looking out for enemies, would also sing praises to God. He doesn’t want His people to keep quiet about what He has done for them.
7 And give him no rest, till he establish, and till He make Jerusalem a praise in the earth.
"Nag" God with praises.
8 The Lord has sworn by His right hand, and by the arm of His strength, Surely I will no more give thy corn to be meat for thine enemies; and the sons of the stranger shall not drink thy wine, for the which thou hast labored:
War and oppression will end.
9 But they that have gathered it shall eat it, and praise the Lord; and they that have brought it together shall drink it in the courts of My holiness.
There will be enough plenty to feast and to resume the feasts in Jerusalem worshiping God.
10 Go through, go through the gates; prepare ye the way of the people; cast up, cast up the highway; gather out the stones; lift up a standard for the people.
11 Behold, the Lord has proclaimed unto the end of the world, Say ye to the daughter of Zion, Behold, thy Salvation comes; behold, His reward is with Him, and His work before Him.
Jesus is the Salvation of Israel.
12 And they shall call them, "The holy people, The redeemed of the Lord:" and thou shall be called, "Sought out, A city not forsaken."