I'm currently doing a Bible study where all the discussions of Christ's work [and all the discussions of the Final Judgment] are collected together. I find these aggregations useful because they often reveal patterns not obvious from casual reading. Indeed, my very first blog was on how the evangelism shown in Acts is really not what we would expect given what most people are taught as "the gospel." [that post is here.]
While doing this I ran across Matthew 8:16-17. The interesting thing about this passage is that it puts a completely different frame on the "Suffering servant" prophecy of Isaiah 53.
The standard explanation of the prophesy in Isaiah 53:4-5 is that Christ took our sins upon Himself. Now, there is an immediate problem with this in that Isaiah describes the sacrifice of the suffering servant as a "reparation/guilt sacrifice"in Isaiah 53:10. This sacrifice was not one where the offenses were placed upon the sacrifice (indeed, often the "sacrifice" was not even a living creature.) It was a "paying back" not a "transfer of sin."
Indeed, if you read Isaiah 53 you'll see that Christ appears to be offered up as a "guilt offering" for sickness. The wording closely matches the discussion of how one was supposed to deal with lepers who had been healed in Leviticus 13 and 14. The word used in Isaiah 53:10 is the same as the word in Leviticus 14:13 to describe the offering. This was one of the three offerings made to cleanse a leper, allowing him back into the temple.
But Matthew 8:16-17 gives another reason not to see this prophecy as a defense of Penal substitution because Matthew claims Jesus was fulfilling it prior to His death when He healed those around Him. Hence, the focus is not on the infirmity being "placed on" Jesus statutorily, but rather that Jesus was "taking the sin away."
Now, the point here is not that Isaiah 53 was not also pertinent to Jesus' crucifixion. After all, the quotation in Acts 8:32-33 of verses 7 and 8 appear to refer to his death, and 1st Peter 2:24 could hardly be more clear that Christ's death is in mind.
However, Matthew's version proves that there is no requirement for the healing to be through transfer, and 1st Peter concurs that it is healing that is in mind here, not transfer of wrath. [In other words, the state of sickness people were in rather than future divine punishment.]
Neither does 1st Peter's version suggest transfer of guilt. Rather that passage puts Christ forth as an example [1st Peter 2:21] of enduring the persecution that people of God endure and leaving justice up to God [2:23]. The purpose suggested is not "to save us from God's wrath" but "that we may cease from sinning and live for righteousness."
1st peter 3:18 gives a similar reason for Christ's suffering.
Indeed, if one takes 1st Peter 3:1-2 seriously, we have to accept that Peter was very much putting forward a "salvation by Christ's example turning us back to God." 1st Peter 4:1-2 hits this topic again.
Now, I don't want to indicate that I'm supporting a "Christ as good example" salvation here. Indeed, 1st Peter 3:21 shows that Peter is not going for this interpretation either. Christ as a mere "good example" could not have accomplished the sending of the Spirit. I'm merely pointing out that the passages that quote Isaiah 53 (as well as the typology of Isaiah 53:10 and Leviticus 14) do not suggest Christ's sacrifice as substitutionary.
Finally, it should be noted that Isaiah 53:10 is never quoted by an NT writer, and the Hebrew is rather hard to understand, so the application of that verse [both in ways for and against PSA] have to be taken as circumstantial at best.