1. Why do Muslims say this is Muhammad?
2. Is this what is talked about in the Old Testament in chapter 42 of Isaiah? and also in Dueteronomy 18:15
Yes. You are right. Chapter 61 is known as Surah As-Saff (The Rows) and it does contain this meaning in verse six (6).
The name "Ahmad" and the name "Muhammad" both come from the same root "hamad", which is also a name in Arabic. It refers to the "praised one" or the "praising one." Muhammad, peace be upon him, was also called "Ahmad" and he said Ahmad was one of his names. "Hamad" is also one of the names associated with Muhammad, peace be upon him.
Now, regarding the verses you mentioned from the Old Testament (Torah), again you are correct, these do seem to point to the advent of the coming of Muhammad, peace be upon him. For those who might have thought this referred too Jesus, peace be upon him, they should consider a serious comparison between Muhammad and Moses, peace be upon them both and then a comparison between Jesus and Moses, peace be upon them both. It came to me after making this comparison, the logical choice was from the "brethren" of the Isralites as mentioned in Dueteronomy (below), and of course Muhammad is a decend from Ishmael (Ismael in Arabic) and as such, is from their "brethren.'
There are a number of places in the Old Testament talking about the coming of Muhammad, peace be upon him. For instance, in Dueteronomy 18:15 "A prophet like unto Moses".
Consider, first of all, Muhammad, peace be upon him, was born as a descendent of Abraham, peace be upon him, through his first born son, Ishmael (Ismail in Arabic), peace be upon him, to the noble tribe of the Quraish who were the leaders of Makkah in those days. Muhammad's blood line traces directly back to Abraham, peace be upon him.This could certainly point to fulfillment of Old Testament (Torah) prophecies in Deuteronomy (chapter 18:15) of a prophet, like unto Moses from "their brethren."
Here it is in Deuteronomy, chapter 18, from King James Version:
15 The LORD thy God will raise up unto thee a Prophet from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken;
16 According to all that thou desiredst of the LORD thy God in Horeb in the day of the assembly, saying, Let me not hear again the voice of the LORD my God, neither let me see this great fire any more, that I die not.
17 And the LORD said unto me, They have well spoken that which they have spoken.
18 I will raise them up a Prophet from among their brethren, like unto thee, and will put my words in his mouth; and he shall speak unto them all that I shall command him.
19 And it shall come to pass, that whosoever will not hearken unto my words which he shall speak in my name, I will require it of him.
20 But the prophet, which shall presume to speak a word in my name, which I have not commanded him to speak, or that shall speak in the name of other gods, even that prophet shall die.
21 And if thou say in thine heart, How shall we know the word which the LORD hath not spoken?
22 When a prophet speaketh in the name of the LORD, if the thing follow not, nor come to pass, that is the thing which the LORD hath not spoken, but the prophet hath spoken it presumptuously: thou shalt not be afraid of him.
Compare the life of Jesus, peace be upon him to the life of Moses (that is who God is speaking to in this chapter) and then compare the life of Muhammad, peace be upon him, to the life of Moses. And see how many comparisons really fit and how many don't.
[click here for more details on this topic] prophetofislam.com/what_did_he_do.php
And chapter 42 of Isaiah is almost as if you were viewing a brief biography of our prophet, peace be upon him.
Here it is from the Book of Isaiah, chapter 42, in the King James Version:
1 Behold my servant, whom I uphold; mine elect, in whom my soul delighteth; I have put my spirit upon him: he shall bring forth judgment to the Gentiles.
2 He shall not cry, nor lift up, nor cause his voice to be heard in the street.
3 A bruised reed shall he not break, and the smoking flax shall he not quench: he shall bring forth judgment unto truth.
4 He shall not fail nor be discouraged, till he have set judgment in the earth: and the isles shall wait for his 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 cometh 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;
7 To open the blind eyes, to bring out the prisoners from the prison, and them that sit in darkness out of the prison house.
8 I am the LORD: that is my name: and my glory will I not give to another, neither my praise to graven images.
9 Behold, the former things are come to pass, and new things do I declare: before they spring forth I tell you of them.
10 Sing unto the LORD a new song, and his praise from the end of the earth, ye that go down to the sea, and all that is therein; the isles, and the inhabitants thereof.
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.
13 The LORD shall go forth as a mighty man, he shall stir up jealousy like a man of war: he shall cry, yea, roar; he shall prevail against his enemies.
14 I have long time holden my peace; I have been still, and refrained myself: now will I cry like a travailing woman; I will destroy and devour at once.
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.
16 And I will bring the 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 things straight. These things will I do unto them, and not forsake them.
17 They shall be turned back, they shall be greatly ashamed, that trust in graven images, that say to the molten images, Ye are our gods.
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.
21 The LORD is well pleased for his righteousness' sake; he will magnify the law, and make it honourable.
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.
23 Who among you will give ear to this? who will hearken and hear for the time to come?
24 Who gave Jacob for a spoil, and Israel to the robbers? did not the LORD, he against whom we have sinned? for they would not walk in his ways, neither were they obedient unto his law.
25 Therefore he hath poured upon him the fury of his anger, and the strength of battle: and it hath set him on fire round about, yet he knew not; and it burned him, yet he laid it not to heart.
Now to make a fair comparison to what is being said here in the Old Testament, simply go to the website about Prophet Muhammad, peace be upon him, at: Prophetofislam.com/this_man.php
Also See: www.ProphetOfIslam.com
What About New Testament Prophecies of Muhammad?: www.prophetofislam.com/that_prophet.php
And also: http://www.islamnewsroom.com/content/view/314/52/ (questions from a Christian)