This is a message for the faithful remnant.
In verses 1-2 the Lord encourages the faithful to look to their source, rocks reflect the quarry they came from and these people are of Abraham and Sarah. Even though the remnant is small, the Lord can bless them and multiply them.
Verse 3 is full of encouraging promises for the future of this remnant.
- He will comfort Zion
- He will comfort her waste places
- He will make her wilderness like Eden
- Her deserts like gardens
- joy and gladness will be found
- thanksgiving and a melody
How encouraging that must have been for her people to read, not just then but over the centuries to come. And it's become true even today, let alone what He has for her in time. The people came in and were able to successfully turn an empty desert into a bread basket, where Jews from all over the world, as well as Christians can come see the hand of the Lord.
Verse 4 starts a new paragraph and changes the focus from the remnant to God Himself. He gets their attention by referring to them as both His people and His nation. He promises that a law will go forth from Him and His justice will be a light to His people.
"My righteousness is near. My salvation has gone forth, and My arms will judge the peoples; the coastlands will wait for me, and for My arm they will wait expectantly.
Isaiah 51:5
I think verse 5 refers to the world outside of Israel. Although their is coastland in Israel, I think I remember that this is one way they refer to the far off nations. And the use of the plural with the word "peoples" also makes me think of many people groups. His salvation and His judgement are for the whole world.
Verse 6 supports my theory. The sky will vanish and the earth will wear out and the people will die; but His salvation and righteousness live forever.
Verses 7-8 continue in this theme, encouraging the faithful remnant, who have God's law written on their hearts. Don't fear men who revile you because they will eventually die, but God's salvation and righteousness are eternal.
Verse 9 starts a new paragraph and has a new speaker. The quote marks closed in verse 8, and the speaker seems to be speaking to the Lord, so it must be Isaiah speaking. He calls out to the Lord and asks Him to act as He has ion the past, defeating Rahab (Egypt) and parting the Red Sea for their escape. He is so confident that the Lord will do it again, spring them from their captivity, he proclaims that they will be ransomed with an everlasting joy and gladness, sorrow fleeing away.
Verses 12-13 are the Lord speaking again.
- I comfort you.
- Why are you afraid of man, who dies?
- You forgot the Lord who made heaven and earth
- you fear the oppressor, but where is he?
Verse 14-15 promises that the exile will be set free and they will not lack because of who He is. He made them and made them His people.
Verses 17-20 are back to Isaiah as the speaker.
- He tells the people of Jerusalem to rouse themselves
- He calls them those who have drunk from the cup of the Lord's hand of His anger
- Having drunk ever last dreg and reeling from it
- No leaders remain who can lead her out
- And no one to mourn for them in all of the bad things that will befall her, devastation, destruction, famine, sword
- their sons faint and lie in the street like an antelope in a net (what a pathetic image of them)
- All of this is because of the wrath and rebuke of the Lord
But Isaiah offers hoe for the afflicted in verse 21-23.
- The Lord contends for his people
- He takes from them His cop of anger and reeling
- They will never drink from it again
- He will put that cup into the hands of their tormentors who humiliated and walked on you.