Thanksgiving hymn

Isa. 12:1] And in that day thou shalt say, O LORD, I will praise thee: though thou wast angry with me, thine anger is turned away, and thou comfortedst me.
In that day - When this great work of the reduction of Israel and conversion of the Gentiles is fulfilled.
Though thou wast angry - "For though thou hast been angry but thanks be to G-d, that ye were the slaves of sin; but have obeyed from the heart. But there is also a sense in which we receive chastening or discipline from G-d, which certainly feels like His anger. This chastening feels unpleasant (Hebrews 11:11), but it really shows the fatherly love of G-d instead of His hatred.
In the sense of G-d's chastening or discipline in our lives, how wonderful it is when His anger is turned away, and "spanking" stops!
G-d disciplines us as a perfect parent, knowing perfectly how to comfort us after we have been chastened. Sometimes, like rebellious children, we refuse the comfort of
G-d after discipline, but that is always our fault, not His.
Satan also tempts us by all methods, and employs every expedient to compel us to despair. We ought, therefore, to be fortified by this doctrine, that, though we feel the anger of the G-d, we may know that it is of short duration, and that we shall be comforted as soon as He has chastened us.
[2] Behold, God is my salvation; I will trust, and not be afraid: for the LORD JEHOVAH is my strength and my song; he also is become my salvation.
The worshipper wants others to see what He says is true. He is excited about what
G-d has done in his life, and invites all to behold the work of the Father.
The talk about trying to believe and trust is a mere pretence. But whether pretence or no, let me remind you that there is no text in the Bible which says, 'Try to trust and believe’.
This peace and security comes from knowing that G-d is my salvation. When we are our own salvation, it is hard to trust and not be afraid in ourselves.
But when G-d is our salvation, we can trust and not be afraid.
This is a confident statement reflecting the will of the worshipper. He is deciding to trust and not be afraid. There are feelings of trust, but that is different than the decision to trust. We can say to our will, "I will trust and not be afraid."
When the G-d is our strength, it means that He is our resource, He is our refuge.
We look to Him for our needs, and are never unsatisfied. Nor is He here called a part or an aid of our strength, but our complete strength; for we are strong, so far as He supplies us with strength.
This chapter is a Thanksgiving hymn of the restored and converted Jews. Just as Miriam, after the deliverance of the Red Sea (11:16), celebrated it with an ode of praise (Ex 15:1-19).
When G-d is our song, it means that He is our joy, He is our happiness. We find our purpose and life in Him, and He never disappoints.
Many don't ever feel the need for salvation. Instead, they think their lives are fine, and come to G-d for a little help when they feel they need it. But they never see themselves as drowning men in need of rescue, or see themselves as hell-destined sinners in need of salvation.
The worshipper is so immersed in this idea that he repeats it in the same verse:
G-d is my salvation . . . He also has become my salvation.
The idea of salvation was peculiarly associated with the Feast of Tabernacles
(verse 3). Hence the cry "Hosanna," "Save, we beseech thee," that accompanied Y’Shuas’ triumphal entry into Jerusalem on that day (the fifteenth of the seventh month) (Matt 21:9; compare with Ps 118:25, 26); the earnest of the perfected "salvation" which He shall bring to His people at His glorious second appearance at Jerusalem (Heb. 9:28). "He shall appear the second time without sin unto salvation." Compare Rev. 21:3, "The Tabernacle of G-d is with men." Compare Lk. 9:33, "three tabernacles: one for thee". (the transfiguration being a pledge of the future kingdom), (Ps 118:15; Zec. 14:16). As the Jew was reminded by the
Feast of Tabernacles of his wanderings in tents in the wilderness, so the Jew-Gentile Church to come shall call to mind, with thanksgiving, the various past ways whereby G-d has at last brought them to the heavenly "city of habitation" (Ps 107:7).
[3] Therefore with joy shall ye draw water out of the wells of salvation.
Your thirsty souls shall be filled with Divine graces and comforts, which you may draw from G-d, in the use of gospel-ordinances.
Be of good courage, you very, very timid ones, and alter your tone. Try to put a 'Selah' into your life, as David often did in his Psalms. Frequently, he put in a 'Selah,' and then he changed the key directly. In like manner, change the key of your singing; you are a great deal too low. Let the harp-strings be screwed up a bit, and let us have no more of this fiat, mournful notes.
Draw water out of the wells of salvation is an expressive image in a hot country.
On the last day of the Feast of Tabernacles the Jews used to bring water in a golden pitcher from the fountain of Siloam, and pour it, mingled with wine, on the sacrifice on the altar, with great rejoicing. This is the allusion in Y’Shuas' words on "the last day of the feast" (John 7:2, 37-39). The pouring out of water indicated repentance (1 Sam. 7:6; compare, as to the Jews' repentance hereafter, Zec. 12:10). There shall be a latter outpouring of the Spirit like the former one on what we call Pentecost (Joe 2:23).
Wells not mere streams, which may run dry, but ever-flowing fountains (John 4:14; 7:38), "Out of his belly (that is, in and from Himself) - living water" (42:18; Ps 84:6; Zec. 13:1; Re 7:17).
When we remember the semi-arid climate of Israel, we see what a beautiful picture the wells of salvation paint. When water is rare, a well is life. To have a place where you can continually come and draw forth to meet your need is a precious gift.
This means there is something for us to do: You will draw water. G-d's doesn't meet our needs as we sit in passive inactivity. We must reach out and draw forth what He has provided. At the same time, it is His water, His well, His rope, and His bucket that we draw with!
The water is Divine knowledge and the wells the teachers of righteousness. The Targum renders this in a very remarkable manner: "Ye shall receive with joy.”
[4] And in that day shall ye say, Praise the LORD, call upon his name, declare his doings among the people, make mention that his name is exalted.
Make him your Mediator, or call the people in His name. Preach Him who is the Root of Jesse, and who stands as an ensign for the nations. Call on the people to believe in Him; as in Him alone salvation is to be found.
Make mention in Hebrew, "cause it to be remembered."
[5] Sing unto the LORD; for he hath done excellent things: this is known in all the earth.
Sing is alluding to Ex 15:21.
[6] Cry out and shout, thou inhabitant of Zion: for great is the Holy One of Israel in the midst of thee.
For great is the Holy One of Israel in your midst: This gives two reasons for great praise. First, because of who G-d is: the Holy One of Israel. Second, because of where G-d is: in your midst.
Each of these gives everyone reason to praise G-d!
Hebrew, "inhabitress"; so "daughter of Zion," that is, Zion and its people. Not only the Jewish people, to whom His word of salvation was to be sent first; but also all believers of the Messianic Church: as in them the Holy One of Israel dwells. Paul, speaking of the mystery which had been proclaimed among the Gentiles, sums it up in these words: "which is the Messiah in you, the hope of glory; whom we preach, warning every man, and teaching every man in all wisdom, that we may present every man perfect in Y’Shua HaMashiach;" Col. 1:27,28. Well, therefore, may the inhabitant of Zion cry oat and shout, and proclaim the greatness of her Redeemer.
In the midst of Jerusalem literally (Jer. 3:17; Ezek. 48:35; Zep. 3:15, 17; Zec. 2:10).
The last three verses here carry repeated instructions to God's people of all ages:
1. Give thanks to Jehovah;
2. Call upon His name;
3. Declare His doings among the people;
4. Make mention that His name is exalted;
5. Sing unto Jehovah;
6. G-d hath done excellent things; let this be known in all the earth;
7. Cry aloud and shout, thou inhabitant of Zion; for great in the midst of thee is the Holy One of Israel.
This brings us to the conclusion of the first great division of Isaiah's prophecy; and in these brief chapters there has emerged the great majority of the themes that Isaiah will discuss throughout the book, "line upon line, here a little and there a little". Such things as ruin and captivity of Israel, the return of a remnant,
G-d's judgments upon wicked nations, the salvation of an obedient remnant, the accomplishment of that redemption by the hand of Immanuel (the Messiah), the coming of the Messiah through the Davidic line, the virgin birth of Messiah, the Messiah's character, His endowment, His ability, the nature of G-d's kingdom, the calling of the Gentiles and their reception into G-d's fellowship and kingdom along with a remnant of the Jews.