Until "...delighted"
If we consider "mine elect" as a noun then Mine elect = God's elect = Mustafa (in Arabic) the name of our Prophet Muhammad Mustafa (SAV). Otherwise it is true for all prophets of God.
After "..delighted..."
All prophets after Jacob (pbuh) mentioned in the Bible came for Israelites not Gentiles. This includes Jesus (pbuh) (look Matthew 15:21-26, Matthew 10:5-6 and many more). And Jesus (pbuh) did not stay on earth long enough to do that. But Muhammad (pbuh) was a Gentile and he brought message and judgment to Gentiles first.
2- He shall not cry, nor lift up, nor cause his voice to be heart in the street.
Here the word "not cry" is used as "not complain about the duty that I gave him" because we see in verse 13 God says "... he shall cry". There is a difference between these two using of the word cry. Now if we read your Bible Matthew 26:39-42, we can not say that Jesus (pbuh) never complained.
But if you read the life of Muhammad (pbuh) , the history of Islam you cannot find even one complaining word of Muhammad (pbuh) about the mission (duty) that given by God Almighty.
3- A bruised reed shall he not break, and the smoking flax shall he not quench: he shall bring forth judgment unto truth.
This is true almost all prophets.
4- He shall not fall nor be discouraged, till he had set judgment in the earth: and the isles shall wait for his law.
Until "earth:"
Jesus (pbuh) couldn't finish his mission which had continued only for ~3 years. He fall and discouraged (you will find many places in NT about this) and he couldn't set judgment in the earth, because his followers were a few and they had little faith (you will find many places in NT about this). And yet they "forsook him and fled" at the time that Roman soldiers came to arrest Jesus (pbuh). And Jesus (pbuh) himself says "My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence " John 18:36
But Muhammad established a state and ruled with his law that given by God. Therefore he set judgment in the earth and he did not fall and he was not discouraged.
After "earth:"
Here God says "his law", and in verse 9 says "former things come to pass". This means that he (new prophet) will bring new law. But if we read the Bible again, we see that Jesus (pbuh) says Matthew 5:17 "Think not I am come to destroy the law, or the prophets: I am not come to destroy but fulfill". And if we read further we understand that Jesus (pbuh) did not come with new law.
But Muhammad (pbuh) came with new law.
5- Thus saith God the Lord, he that created the heavens, and stretched them out; he that spread forth the earth, and that which come out of it ; he that giveth breath unto the people upon it, and spirit to them that walk therein;
6- I the Lord have called thee in righteousness, and will hold thine hand, and will keep thee, and give thee for a covenant of the people, for a light of the Gentiles.
Muhammad (pbuh) is a descendent of Abraham (pbuh) and came to Gentiles.
7- To open blind eyes, to bring out prisoners from prison, and them that sit in darkness out of the prison house.
"To open blind eyes". If we read verse 19 we will see more clearly that the word blind is used as idiom.
Meaning, he will show people the things that they did not know and will show people how to comprehend God and His message.
Prison is used as an idiom too. If a spirit doesn't know God and doesn't obey Him, then that spirit is in prison of Satan, and that person is prisoner of Satan. By accepting oneness of God and by obeying Him, the spirit of a person will be free and this makes that person free from prison of Satan. And in verse 8 God clearly states what He meant.
8- I am the Lord: that is my name: and my glory will I not give to another, neither my praise to graven images.
(With explanation of verse 7) we understand that the person that God is talking about will come to a place that people worship idols as their gods. If we read verse 17, we may understand this better.
From verses 7 and 8, we understand that God is not talking about Jesus (pbuh) but Muhammad (pbuh). Because Jesus (pbuh) came to Israelites and they were not worshipping idols. But Muhammad (pbuh) came during the Jahilliya (ignorance) period of Arabs and destroy the idols. If we read verse 17, it will be understood more clearly.
9- Behold, the former things come to pass, the new things do I declare: before they spring forth I tell you of them.
As we read in verse 4 and my explanation of it, the person, God is talking about, will come new law. And this person cannot be Jesus (pbuh) because of the reasons stated above. This person is nobody but prophet Muhammad (pbuh).
10- Sing unto the Lord a new song, and his praise, ye that go down to the sea, and all that is therein; the isles and inhabitants thereof.
If you want to hear this new song please listen to someone reciting the Qur'an. The new song that God talking about is Noble Qur'an. If you hear how people recite the Noble Qur'an, you will understand what God is talking about.
11- Let the wilderness and the cities thereof lift up their voice, the villages that Kedar doth inhabit: let the inhabitants of the rock sing, let them shout from the top of the mountains.
12- Let them give glory unto the Lord, and declare his praise in the islands.
Kedar is son of Ishmael (pbuh) (Genesis 25:13-16), and has nothing to do with Jesus (pbuh). This verse (verse 11) is not talking about Jesus (pbuh) but Muhammad (pbuh). As you know Muhammad (pbuh) is descendent of Abraham (pbuh) through Ishmael (pbuh). And the cities that they inhabited are in Arabia namely Telma (Tema/Teman), Yathrib (Al-Madinah Al-Munawwarah), Paran (Makkah) etc. And if you observe the ritual of Muslims (especially during Hajj), you will see that cities (Makkah and Al-Madinah) lift up their voices** and people shout and glorify Allah from top of mountains, especially Mt. Arafat**. The rock is the rock that God sent to Adam from heaven, and it is located at the side of Kaba. As you know Muslim people make 7 tours around Kaba and kiss this rock while glorifying the Lord.
Allah is the greatest, Allah is the greatest
Allah is the greatest, Allah is the greatest
I'm witness that there is no god but Allah
I'm witness that there is no god but Allah
I'm witness that Muhammad is His messenger
Come to prayer, come to prayer
Come to salvation, come to salvation
Allah is the greatest, Allah is the greatest
There is no god but Allah.
15- I will make waste mountains and hills, and dry up all their herbs; and I will make the rivers islands, and I will dry up the pools.
Here God is talking about deserts of Arabia. In desert place, mountains and hills of sand are not steady, they diminish with winds and another one appears. And you can not find rivers but small water islands as described by God.
Also this verse has nothing to do with Jesus (pbuh)
16- And I will bring blind by a way that they knew not; I will lead them in paths that they have not known: I will make darkness light before them, and crooked thins straight. These things I will do unto them, and not forsake them.
As God says above, He did not send to pagan Arabs until Muhammad (pbuh) as stated in verse
17- They shall be turned back, they shall be greatly ashamed, that trust in graven images, that they say to the molten images, Ye are our gods.
This is exactly what pagan Arabs did, when they heard the message that given to Muhammad (pbuh) by God. They offered money, authority and many things to our prophet and he did not accept any of them. They ashamed, because they thought that all other Arabs will mock them, and will not visit the Kaba (at that time they were using Kaba as place of the idols that all other Arab tribes were using) and this would be their economic end. And they turned graven images and they asked help from those images.
This verse also has nothing to do with Jesus (pbuh).
18- Hear, ye deaf; and look, ye blind, that ye may see.
19- Who is blind, but my servant? or deaf, as my messenger that I sent? who is blind as he that is perfect, and blind as the Lord's servant?
20- Seeing many things, but thou observest not; opening the ears, but he heareth not.
In this verses God talks to Christians and Jews.
In verse 18: Hear you (Christians and Jews) deaf, and look you (Christians and Jews) blind, you may see that above things are happening every day in Islamic world.
In verse 19: God says, "Who is blind or deaf? My messenger (Muhammad (pbuh) and his followers) or you?
In verse 20: You do see these things but you don't pay attention, you don't comprehend. You do hear the Qur'an and you know that Muslims sing new song and Muslim cities lift up their voices and they shout from top of mountains, they glorify Me, but you don't pay attention, you don't comprehend.
Indeed, Christians and Jews think that Muslims do not see the right path (blind). Even you wrote that "What Muslims do not understand...".
These verses also have nothing to do with Jesus (pbuh).
21- The Lord is well pleased for his righteousness' sake; he will magnify the law, and make it honourable.
In Qur'an many places Allah calls Prophet as "My friend" (friend is not exactly translation for Habeeb/Habib, because Habeeb is closer then friend but I couldn't find another word for this). And He magnified the law and people still follow his law. Jesus did not bring new law, and non of the Christians follows the law that he was following.
This verse also has nothing to do with Jesus (pbuh)
22- But this is a people robbed and spoiled; they are all of them snared in holes, and they are hid in prison houses: they are for a prey, and none delivereth; for a spoil, and none saith, Restore.
In this verse God talks about corrupted society of pagan Arabs. And, indeed, He had not send any prophets to Arabs until Muhammad (pbuh). That's why "none saith, Restore". But up to Jesus (pbuh), many prophets had been send to Israelites.
This verse also has nothing to do with Jesus (pbuh)
23- Who among you will give ear to this? who will hearken and hear for the time to come?
Who will become Muslim?
Conclusion:
Isaiah 42 describes Prophet Muhammad.