The test case is the explanation of Isaiah 52:7–10. Although most modern readers would quail at having an explanation of any part of Isaiah determine their fate, Abinadi is undaunted. The question here, however, is why this passage?
The answer is complicated, and cannot be fully answered until the full evidence of the discussion has been seen. However, just as Mormon could foreshadow what Abinadi would do before recording it, we too can suggest the reason for this passage based on what will come.
The religion in the court of Noah has many corollaries to what will be known as The Order of the Nehors. One of the important aspects of that religion is adherence to the law of Moses, but rejection of the coming atoning Messiah. That will be the essential message of Abinadi’s trial.
The passage from Isaiah deals with salvation, and declares that “the Lord hath made bare his holy arm in the eyes of all the nations, and all the ends of the earth shall see the salvation of our God.” Thus, the priests of Noah will be arguing that the scriptures have already declared that salvation comes through Jehovah. That would mean that there was no need for a future atoning Messiah. Not entirely without reason, the priests would see the phrase “he hath redeemed Jerusalem” as the redemption of the people, not the city. Hence, they have scriptural proof that Jehovah has already redeemed his people.