From UCRT on 11:1

The prophet having described the destruction of the Assyrian army under that of a mighty forest, here takes occasion to represent the great Person, who makes the subject of this chapter, as a slender twig, shooting out of the trunk of an old tree; which tender twig, though weak in appearance, should become fruitful and prosper.

(ט) כִּֽי־הִנֵּ֤ה אָֽנֹכִי֙ מְצַוֶּ֔ה וַהֲנִע֥וֹתִי בְכָֽל־הַגּוֹיִ֖ם אֶת־בֵּ֣ית יִשְׂרָאֵ֑ל כַּאֲשֶׁ֤ר יִנּ֙וֹעַ֙ בַּכְּבָרָ֔ה וְלֹֽא־יִפּ֥וֹל צְר֖וֹר אָֽרֶץ׃ (י) בַּחֶ֣רֶב יָמ֔וּתוּ כֹּ֖ל חַטָּאֵ֣י עַמִּ֑י הָאֹמְרִ֗ים לֹֽא־תַגִּ֧ישׁ וְתַקְדִּ֛ים בַּעֲדֵ֖ינוּ הָרָעָֽה׃ (יא) בַּיּ֣וֹם הַה֔וּא אָקִ֛ים אֶת־סֻכַּ֥ת דָּוִ֖יד הַנֹּפֶ֑לֶת וְגָדַרְתִּ֣י אֶת־פִּרְצֵיהֶ֗ן וַהֲרִֽסֹתָיו֙ אָקִ֔ים וּבְנִיתִ֖יהָ כִּימֵ֥י עוֹלָֽם׃ (יב) לְמַ֨עַן יִֽירְשׁ֜וּ אֶת־שְׁאֵרִ֤ית אֱדוֹם֙ וְכָל־הַגּוֹיִ֔ם אֲשֶׁר־נִקְרָ֥א שְׁמִ֖י עֲלֵיהֶ֑ם נְאֻם־יְהוָ֖ה עֹ֥שֶׂה זֹּֽאת׃ (פ)

(9) For I will give the order And shake the House of Israel— Through all the nations— As one shakes [sand] in a sieve, And not a pebble falls to the ground. (10) All the sinners of My people Shall perish by the sword, Who boast, “Never shall the evil Overtake us or come near us.” (11) In that day, I will set up again the fallen booth of David: I will mend its breaches and set up its ruins anew. I will build it firm as in the days of old, (12) So that they shall possess the rest of Edom And all the nations once attached to My name —declares the LORD who will bring this to pass.

From the Cambidge Bible Commentary

It is interesting to compare this passage with ch. Isa_9:1-7. There the delineation of the Messianic age starts from its broadest and most general features—the light breaking on the land, the universally diffused joy of the redeemed nation—and only at the end centres itself in the person of the Wonderful Child who is born to ascend the throne. Here the person of the Messiah comes first, and then the healing and regenerating influences of which he is the channel. To what period of Isaiah’s career the prophecy belongs cannot be determined.

The affinity with ch. Isa_9:1-7 suggests the reign of Ahaz, to which it is assigned by Guthe in accordance with a particular theory of the development of Isaiah’s eschatology. But since there is no evidence that the idea of the Messianic King ever lost its significance to the prophet’s mind, it might with equal propriety be referred to any subsequent period of his ministry. Duhm places this and the companion oracles of Isa_2:2-4, Isa_32:1-5 in the evening of Isaiah’s long life. In its present setting the passage is no doubt intended as a sequel to ch. Isa_10:5-34 and it might even belong to the same date.

(א) הָעָם֙ הַהֹלְכִ֣ים בַּחֹ֔שֶׁךְ רָא֖וּ א֣וֹר גָּד֑וֹל יֹשְׁבֵי֙ בְּאֶ֣רֶץ צַלְמָ֔וֶת א֖וֹר נָגַ֥הּ עֲלֵיהֶֽם׃ (ב) הִרְבִּ֣יתָ הַגּ֔וֹי לא [ל֖וֹ] הִגְדַּ֣לְתָּ הַשִּׂמְחָ֑ה שָׂמְח֤וּ לְפָנֶ֙יךָ֙ כְּשִׂמְחַ֣ת בַּקָּצִ֔יר כַּאֲשֶׁ֥ר יָגִ֖ילוּ בְּחַלְּקָ֥ם שָׁלָֽל׃ (ג) כִּ֣י ׀ אֶת־עֹ֣ל סֻבֳּל֗וֹ וְאֵת֙ מַטֵּ֣ה שִׁכְמ֔וֹ שֵׁ֖בֶט הַנֹּגֵ֣שׂ בּ֑וֹ הַחִתֹּ֖תָ כְּי֥וֹם מִדְיָֽן׃ (ד) כִּ֤י כָל־סְאוֹן֙ סֹאֵ֣ן בְּרַ֔עַשׁ וְשִׂמְלָ֖ה מְגוֹלָלָ֣ה בְדָמִ֑ים וְהָיְתָ֥ה לִשְׂרֵפָ֖ה מַאֲכֹ֥לֶת אֵֽשׁ׃ (ה) כִּי־יֶ֣לֶד יֻלַּד־לָ֗נוּ בֵּ֚ן נִתַּן־לָ֔נוּ וַתְּהִ֥י הַמִּשְׂרָ֖ה עַל־שִׁכְמ֑וֹ וַיִּקְרָ֨א שְׁמ֜וֹ פֶּ֠לֶא יוֹעֵץ֙ אֵ֣ל גִּבּ֔וֹר אֲבִיעַ֖ד שַׂר־שָׁלֽוֹם׃ (ו) לםרבה [לְמַרְבֵּ֨ה] הַמִּשְׂרָ֜ה וּלְשָׁל֣וֹם אֵֽין־קֵ֗ץ עַל־כִּסֵּ֤א דָוִד֙ וְעַל־מַמְלַכְתּ֔וֹ לְהָכִ֤ין אֹתָהּ֙ וּֽלְסַעֲדָ֔הּ בְּמִשְׁפָּ֖ט וּבִצְדָקָ֑ה מֵעַתָּה֙ וְעַד־עוֹלָ֔ם קִנְאַ֛ת יְהוָ֥ה צְבָא֖וֹת תַּעֲשֶׂה־זֹּֽאת׃ (ס)

(1) The people that walked in darkness Have seen a brilliant light; On those who dwelt in a land of gloom Light has dawned. (2) You have magnified that nation, Have given it great joy; They have rejoiced before You As they rejoice at reaping time, As they exult When dividing spoil. (3) For the yoke that they bore And the stick on their back— The rod of their taskmaster— You have broken as on the day of Midian. (4) Truly, all the boots put on to stamp with And all the garments donned in infamy Have been fed to the flames, Devoured by fire. (5) For a child has been born to us, A son has been given us. And authority has settled on his shoulders. He has been named “The Mighty God is planning grace; The Eternal Father, a peaceable ruler”— (6) In token of abundant authority And of peace without limit Upon David’s throne and kingdom, That it may be firmly established In justice and in equity Now and evermore. The zeal of the LORD of Hosts Shall bring this to pass. (7) My Lord Let loose a word against Jacob And it fell upon Israel.

(א) הַדָּבָר֙ אֲשֶׁ֣ר חָזָ֔ה יְשַֽׁעְיָ֖הוּ בֶּן־אָמ֑וֹץ עַל־יְהוּדָ֖ה וִירוּשָׁלִָֽם׃ (ב) וְהָיָ֣ה ׀ בְּאַחֲרִ֣ית הַיָּמִ֗ים נָכ֨וֹן יִֽהְיֶ֜ה הַ֤ר בֵּית־יְהוָה֙ בְּרֹ֣אשׁ הֶהָרִ֔ים וְנִשָּׂ֖א מִגְּבָע֑וֹת וְנָהֲר֥וּ אֵלָ֖יו כָּל־הַגּוֹיִֽם׃ (ג) וְֽהָלְכ֞וּ עַמִּ֣ים רַבִּ֗ים וְאָמְרוּ֙ לְכ֣וּ ׀ וְנַעֲלֶ֣ה אֶל־הַר־יְהוָ֗ה אֶל־בֵּית֙ אֱלֹהֵ֣י יַעֲקֹ֔ב וְיֹרֵ֙נוּ֙ מִדְּרָכָ֔יו וְנֵלְכָ֖ה בְּאֹרְחֹתָ֑יו כִּ֤י מִצִּיּוֹן֙ תֵּצֵ֣א תוֹרָ֔ה וּדְבַר־יְהוָ֖ה מִירוּשָׁלִָֽם׃ (ד) וְשָׁפַט֙ בֵּ֣ין הַגּוֹיִ֔ם וְהוֹכִ֖יחַ לְעַמִּ֣ים רַבִּ֑ים וְכִתְּת֨וּ חַרְבוֹתָ֜ם לְאִתִּ֗ים וַחֲנִיתֽוֹתֵיהֶם֙ לְמַזְמֵר֔וֹת לֹא־יִשָּׂ֨א ג֤וֹי אֶל־גּוֹי֙ חֶ֔רֶב וְלֹא־יִלְמְד֥וּ ע֖וֹד מִלְחָמָֽה׃ (פ)

(2) In the days to come, The Mount of the LORD’s House Shall stand firm above the mountains And tower above the hills; And all the nations Shall gaze on it with joy. (3) And the many peoples shall go and say: “Come, Let us go up to the Mount of the LORD, To the House of the God of Jacob; That He may instruct us in His ways, And that we may walk in His paths.” For instruction shall come forth from Zion, The word of the LORD from Jerusalem. (4) Thus He will judge among the nations And arbitrate for the many peoples, And they shall beat their swords into plowshares And their spears into pruning hooks: Nation shall not take up Sword against nation; They shall never again know war.

Some nice recurring ideas:

(ט) לֹֽא־יָרֵ֥עוּ וְלֹֽא־יַשְׁחִ֖יתוּ בְּכָל־הַ֣ר קָדְשִׁ֑י כִּֽי־מָלְאָ֣ה הָאָ֗רֶץ דֵּעָה֙ אֶת־יְהוָ֔ה כַּמַּ֖יִם לַיָּ֥ם מְכַסִּֽים׃ (פ)

(9) In all of My sacred mount Nothing evil or vile shall be done; For the land shall be filled with devotion to the LORD As water covers the sea.

(יד) כִּ֚י תִּמָּלֵ֣א הָאָ֔רֶץ לָדַ֖עַת אֶת־כְּב֣וֹד יְהוָ֑ה כַּמַּ֖יִם יְכַסּ֥וּ עַל־יָֽם׃ (ס)

(14) For the earth shall be filled With awe for the glory of the LORD As water covers the sea.

(לא) הִנֵּ֛ה יָמִ֥ים בָּאִ֖ים נְאֻם־יְהוָ֑ה וְכָרַתִּ֗י אֶת־בֵּ֧ית יִשְׂרָאֵ֛ל וְאֶת־בֵּ֥ית יְהוּדָ֖ה בְּרִ֥ית חֲדָשָֽׁה׃ (לב) לֹ֣א כַבְּרִ֗ית אֲשֶׁ֤ר כָּרַ֙תִּי֙ אֶת־אֲבוֹתָ֔ם בְּיוֹם֙ הֶחֱזִיקִ֣י בְיָדָ֔ם לְהוֹצִיאָ֖ם מֵאֶ֖רֶץ מִצְרָ֑יִם אֲשֶׁר־הֵ֜מָּה הֵפֵ֣רוּ אֶת־בְּרִיתִ֗י וְאָנֹכִ֛י בָּעַ֥לְתִּי בָ֖ם נְאֻם־יְהוָֽה׃ (לג) כִּ֣י זֹ֣את הַבְּרִ֡ית אֲשֶׁ֣ר אֶכְרֹת֩ אֶת־בֵּ֨ית יִשְׂרָאֵ֜ל אַחֲרֵ֨י הַיָּמִ֤ים הָהֵם֙ נְאֻם־יְהוָ֔ה נָתַ֤תִּי אֶת־תּֽוֹרָתִי֙ בְּקִרְבָּ֔ם וְעַל־לִבָּ֖ם אֶכְתֲּבֶ֑נָּה וְהָיִ֤יתִי לָהֶם֙ לֵֽאלֹהִ֔ים וְהֵ֖מָּה יִֽהְיוּ־לִ֥י לְעָֽם׃ (לד) וְלֹ֧א יְלַמְּד֣וּ ע֗וֹד אִ֣ישׁ אֶת־רֵעֵ֜הוּ וְאִ֤ישׁ אֶת־אָחִיו֙ לֵאמֹ֔ר דְּע֖וּ אֶת־יְהוָ֑ה כִּֽי־כוּלָּם֩ יֵדְע֨וּ אוֹתִ֜י לְמִקְטַנָּ֤ם וְעַד־גְּדוֹלָם֙ נְאֻם־יְהוָ֔ה כִּ֤י אֶסְלַח֙ לַֽעֲוֺנָ֔ם וּלְחַטָּאתָ֖ם לֹ֥א אֶזְכָּר־עֽוֹד׃ (ס)

(31) See, a time is coming—declares the LORD—when I will make a new covenant with the House of Israel and the House of Judah. (32) It will not be like the covenant I made with their fathers, when I took them by the hand to lead them out of the land of Egypt, a covenant which they broke, though I espoused them—declares the LORD. (33) But such is the covenant I will make with the House of Israel after these days—declares the LORD: I will put My Teaching into their inmost being and inscribe it upon their hearts. Then I will be their God, and they shall be My people. (34) No longer will they need to teach one another and say to one another, “Heed the LORD”; for all of them, from the least of them to the greatest, shall heed Me—declares the LORD. For I will forgive their iniquities, And remember their sins no more.

Reconciliation

(יג) וְסָ֙רָה֙ קִנְאַ֣ת אֶפְרַ֔יִם וְצֹרְרֵ֥י יְהוּדָ֖ה יִכָּרֵ֑תוּ אֶפְרַ֙יִם֙ לֹֽא־יְקַנֵּ֣א אֶת־יְהוּדָ֔ה וִֽיהוּדָ֖ה לֹֽא־יָצֹ֥ר אֶת־אֶפְרָֽיִם׃
(13) Then Ephraim’s envy shall cease And Judah’s harassment shall end; Ephraim shall not envy Judah, And Judah shall not harass Ephraim.

Is Isaiah serious??? That's a tall order!:

(יח) בְּעֶבְרַ֛ת יְהוָ֥ה צְבָא֖וֹת נֶעְתַּ֣ם אָ֑רֶץ וַיְהִ֤י הָעָם֙ כְּמַאֲכֹ֣לֶת אֵ֔שׁ אִ֥ישׁ אֶל־אָחִ֖יו לֹ֥א יַחְמֹֽלוּ׃ (יט) וַיִּגְזֹ֤ר עַל־יָמִין֙ וְרָעֵ֔ב וַיֹּ֥אכַל עַל־שְׂמֹ֖אול וְלֹ֣א שָׂבֵ֑עוּ אִ֥ישׁ בְּשַׂר־זְרֹע֖וֹ יֹאכֵֽלוּ׃ (כ) מְנַשֶּׁ֣ה אֶת־אֶפְרַ֗יִם וְאֶפְרַ֙יִם֙ אֶת־מְנַשֶּׁ֔ה יַחְדָּ֥ו הֵ֖מָּה עַל־יְהוּדָ֑ה בְּכָל־זֹאת֙ לֹא־שָׁ֣ב אַפּ֔וֹ וְע֖וֹד יָד֥וֹ נְטוּיָֽה׃ (ס)

(18) By the fury of the LORD of Hosts, The earth was shaken. Next, the people became like devouring fire: No man spared his countryman. (19) They snatched on the right, but remained hungry, And consumed on the left without being sated. Each devoured the flesh of his own kindred— (20) Manasseh Ephraim’s, and Ephraim Manasseh’s, And both of them against Judah! Yet His anger has not turned back, And His arm is outstretched still.

And yet...

(א) וַיִּשְׁלַ֨ח יְחִזְקִיָּ֜הוּ עַל־כָּל־יִשְׂרָאֵ֣ל וִֽיהוּדָ֗ה וְגַֽם־אִגְּרוֹת֙ כָּתַב֙ עַל־אֶפְרַ֣יִם וּמְנַשֶּׁ֔ה לָב֥וֹא לְבֵית־יְהוָ֖ה בִּֽירוּשָׁלִָ֑ם לַעֲשׂ֣וֹת פֶּ֔סַח לַיהוָ֖ה אֱלֹהֵ֥י יִשְׂרָאֵֽל׃ (ב) וַיִּוָּעַ֨ץ הַמֶּ֧לֶךְ וְשָׂרָ֛יו וְכָל־הַקָּהָ֖ל בִּירוּשָׁלִָ֑ם לַעֲשׂ֥וֹת הַפֶּ֖סַח בַּחֹ֥דֶשׁ הַשֵּׁנִֽי׃ (ג) כִּ֣י לֹ֧א יָכְל֛וּ לַעֲשֹׂת֖וֹ בָּעֵ֣ת הַהִ֑יא כִּ֤י הַכֹּהֲנִים֙ לֹֽא־הִתְקַדְּשׁ֣וּ לְמַדַּ֔י וְהָעָ֖ם לֹא־נֶאֶסְפ֥וּ לִֽירוּשָׁלִָֽם׃ (ד) וַיִּישַׁ֥ר הַדָּבָ֖ר בְּעֵינֵ֣י הַמֶּ֑לֶךְ וּבְעֵינֵ֖י כָּל־הַקָּהָֽל׃ (ה) וַיַּֽעֲמִ֣ידוּ דָבָ֗ר לְהַעֲבִ֨יר ק֤וֹל בְּכָל־יִשְׂרָאֵל֙ מִבְּאֵֽר־שֶׁ֣בַע וְעַד־דָּ֔ן לָב֞וֹא לַעֲשׂ֥וֹת פֶּ֛סַח לַיהוָ֥ה אֱלֹהֵֽי־יִשְׂרָאֵ֖ל בִּירוּשָׁלִָ֑ם כִּ֣י לֹ֥א לָרֹ֛ב עָשׂ֖וּ כַּכָּתֽוּב׃ (ו) וַיֵּלְכוּ֩ הָרָצִ֨ים בָּֽאִגְּר֜וֹת מִיַּ֧ד הַמֶּ֣לֶךְ וְשָׂרָ֗יו בְּכָל־יִשְׂרָאֵל֙ וִֽיהוּדָ֔ה וּכְמִצְוַ֥ת הַמֶּ֖לֶךְ לֵאמֹ֑ר בְּנֵ֣י יִשְׂרָאֵ֗ל שׁ֚וּבוּ אֶל־יְהוָ֗ה אֱלֹהֵי֙ אַבְרָהָם֙ יִצְחָ֣ק וְיִשְׂרָאֵ֔ל וְיָשֹׁב֙ אֶל־הַפְּלֵיטָ֔ה הַנִּשְׁאֶ֣רֶת לָכֶ֔ם מִכַּ֖ף מַלְכֵ֥י אַשּֽׁוּר׃ (ז) וְאַל־תִּֽהְי֗וּ כַּאֲבֽוֹתֵיכֶם֙ וְכַ֣אֲחֵיכֶ֔ם אֲשֶׁ֣ר מָעֲל֔וּ בַּיהוָ֖ה אֱלֹהֵ֣י אֲבוֹתֵיהֶ֑ם וַיִּתְּנֵ֣ם לְשַׁמָּ֔ה כַּאֲשֶׁ֖ר אַתֶּ֥ם רֹאִֽים׃ (ח) עַתָּ֕ה אַל־תַּקְשׁ֥וּ עָרְפְּכֶ֖ם כַּאֲבוֹתֵיכֶ֑ם תְּנוּ־יָ֣ד לַיהוָ֗ה וּבֹ֤אוּ לְמִקְדָּשׁוֹ֙ אֲשֶׁ֣ר הִקְדִּ֣ישׁ לְעוֹלָ֔ם וְעִבְדוּ֙ אֶת־יְהוָ֣ה אֱלֹהֵיכֶ֔ם וְיָשֹׁ֥ב מִכֶּ֖ם חֲר֥וֹן אַפּֽוֹ׃ (ט) כִּ֣י בְשׁוּבְכֶ֞ם עַל־יְהוָ֗ה אֲחֵיכֶ֨ם וּבְנֵיכֶ֤ם לְרַחֲמִים֙ לִפְנֵ֣י שֽׁוֹבֵיהֶ֔ם וְלָשׁ֖וּב לָאָ֣רֶץ הַזֹּ֑את כִּֽי־חַנּ֤וּן וְרַחוּם֙ יְהוָ֣ה אֱלֹהֵיכֶ֔ם וְלֹא־יָסִ֤יר פָּנִים֙ מִכֶּ֔ם אִם־תָּשׁ֖וּבוּ אֵלָֽיו׃ (פ)

(1) Hezekiah sent word to all Israel and Judah; he also wrote letters to Ephraim and Manasseh to come to the House of the LORD in Jerusalem to keep the Passover for the LORD God of Israel.

...

(4) The king and the whole congregation thought it proper (5) to issue a decree and proclaim throughout all Israel from Beer-sheba to Dan that they come and keep the Passover for the LORD God of Israel in Jerusalem—not often did they act in accord with what was written.

(6) The couriers went out with the letters from the king and his officers through all Israel and Judah, by order of the king, proclaiming, “O you Israelites! Return to the LORD God of your fathers, Abraham, Isaac, and Israel, and He will return to the remnant of you who escaped from the hand of the kings of Assyria. (7) Do not be like your fathers and brothers who trespassed against the LORD God of their fathers and He turned them into a horror, as you see. (8) Now do not be stiffnecked like your fathers; submit yourselves to the LORD and come to His sanctuary, which He consecrated forever, and serve the LORD your God so that His anger may turn back from you. (9) If you return to the LORD, your brothers and children will be regarded with compassion by their captors, and will return to this land; for the LORD your God is gracious and merciful; He will not turn His face from you if you return to Him.”