The Gospel of Luke
The Book of Isaiah

The Gospel of Luke
Here is what you will find under chapter 4:
16And he (Jesus) came to Nazareth, where he had been brought up: and, as his custom was, he went into the synagogue on the Sabbath day, and stood up for to read. 17And there was delivered unto him the book of the prophet Isaiah. And when he had opened the book, he found the place where it was written, 18The Spirit of the Lord is upon me, because he hath anointed me to preach the gospel to the poor; he hath sent me to heal the brokenhearted, to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised, 19To preach the acceptable year of the Lord. 20And he closed the book, and he gave it again to the minister, and sat down. And the eyes of all them that were in the synagogue were fastened on him. 21And he began to say unto them, This day is this scripture fulfilled in your ears. (King James Version 2nd Edition).
Please note the texts that is in Red Ink and is underlined and has Bold Face.
If your copy of the Bible has a cross reference, it will show that the quoted text which is in the red has been reproduced from the Book of Isaiah 61: 1-2. According to Luke, Jesus found and read the above quoted text from the Book of Isaiah. Surprisingly, if you flip the pages and go to the Book of Isaiah in your Bible you will NOT find the underlined TEXT. 

The Book of Isaiah

Here is what you will find under chapter 61:

1The Spirit of the Lord GOD is upon me; because the LORD hath anointed me to preach good tidings unto the meek; he hath sent me to bind up the brokenhearted, to proclaim liberty to the captives, and the opening of the prison to them that are bound; 2To proclaim the acceptable year of the LORD, and the day of vengeance of our God; to comfort all that mourn; 3To appoint unto them that mourn in Zion, to give unto them beauty for ashes, the oil of joy for mourning, the garment of praise for the spirit of heaviness; that they might be called trees of righteousness, the planting of the LORD, that he might be glorified.

The questions I have for those who claim the Gospels are the inspired words of God; How do you justify the addition?

It is highly unlikely that apostle Luke who has quotes several passages from the Old Testament in his Gospel was unaware of the following verse from the Book of Deuteronomy Chapter 4:
2Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the LORD your God which I command you.
Isaiah or Jesus?
Jesus had recovered the SIGHT OF THE BLINDS and Prophet Isaiah had not. But, since the text that speaks of recovering the SIGHT TO THE BLIND does not appear in the "so called original prophecy" by Isaiah, the quoted text very well applies to Isaiah - the author. In other words the opening text that reads; "because the LORD hath anointed me" means "The Lord had Anointed Isaiah.
It is a MISCONCEPTION that Jesus who is called "CHRIST" (meaning the Anointed One), has been the ONLY individual in the Bible that had been Anointed by the LORD. Isaiah records in his book: 
45: 1 Thus saith the LORD to his anointed, to Cyrus, whose right hand I have holden, to subdue nations before him;
Cyrus the King of Persia was a Gentile and not a Jew. The LORD anointed him to subdue the nations and free those who were in the exile. God anoints a Gentile so why not a Jewish Prophet - Isaiah!
Interestingly enough, in chapter 6 Isaiah has recorded that one of the seraphs flew towards him holding a live coal from the alter with a pair of tongs and touched his mouth with that coal and said: "Now that this has touched your lips, your guilt has departed and your sin is blotted out." 
Keeping in the back of ones mind what has been written so far, if one was to read again the entire text of the "so called prophecies" as originally recorded by Isaiah in 61: 1 to 3, most of the prophesized events do not apply to the Ministry of Jesus which ended with persecutions and the his prosecution. As for the passage attributed to Jesus which reads "This day is this scripture fulfilled in your ears", since Luke can ADD a sentence to the RECORDED WORDS OF THE SCRIPTURE, it would not be a formidable task for him to ADD a sentence to the UNRECORDED SPOKEN WORDS.
The Bible scholars and students who have discovered similar passages from the Old Testaments that have been either misquoted or edited by the Gospel writers do often express as under:  
Were the Prophecies from the Old Testaments fulfilled by the genuine history of Jesus or the Gospels were written to fulfill them? 

An endnote that is worth noting:
To prove the above point one need not go any outside source  or any other external document or commentary. It is the Bible proof reading the Bible...

May Allah Guide All to The Eternal Truth