It can’t be Israel because Israel was commanded to offer guilt offerings to God...but the suffering one in Is 53 was the guilt offering Himself (v. 10).
I suggest you do some research on Isaiah 53.Jesus has nothing to do with it.NOTHING.Christianity needs to stop taking our sacred scriptures and twisting them around!!
Jeremiah 31:2 Thus saith YHWH: the people that were left of the sword have found grace in the wilderness, even Israel, when I go to cause him to rest.
God promises the descendants of Israel who, through captivity, exile, and intermarriage with Gentiles became assimilated and inculturated Gentiles today that they will find "grace in the wilderness".
The exile mentioned in Isaiah
From the JPS (1917) Jewish Bible Tanakh Their exile was their atonement. No blood was shed and their sins were taken away.
8 In full measure, when Thou sendest her away, Thou dost contend with her; He hath removed her with His rough blast in the day of the east wind.
9 Therefore by this shall the iniquity of Jacob be expiated, and this is all the fruit of taking away his sin: when he maketh all the stones of the altar as chalkstones that are beaten in pieces, so that the Asherim and the sun-images shall rise no more.