Isa 53 is about particular atonement, and its the scripture ! Now Christ died for our sins according to the scripture Paul preached 1 Cor 15:3-4
3 For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures;
4 And that he was buried, and that he rose again the third day according to the scriptures:
Now no doubt the scriptures Paulhad in mind Im sure are the OT writings, like Isiah- Remember Phillip preached the Gospel from Isiah and it was called scripture Acts 8:30-35
30 And Philip ran thither to him, and heard him read the prophet Esaias, and said, Understandest thou what thou readest?
31 And he said, How can I, except some man should guide me? And he desired Philip that he would come up and sit with him.
32 The place of the scripture which he read was this, He was led as a sheep to the slaughter; and like a lamb dumb before his shearer, so opened he not his mouth:
33 In his humiliation his judgment was taken away: and who shall declare his generation? for his life is taken from the earth.
34 And the eunuch answered Philip, and said, I pray thee, of whom speaketh the prophet this? of himself, or of some other man?
35 Then Philip opened his mouth, and began at the same scripture, and preached unto him Jesus.
Now neither Paul or Phillip could have preached from Isaiah 53 and not preach limited, particular atonement. The eunuch would have heard a sermon on particular atonement, for it said Phillip preached to him from Isaiah 53 Jesus
It was prophesied Jesus shall save HIS People from their sins Matt 1:21