Abinadi, of all the people we meet in the Book of Mormon, came the closest to actually experiencing what Jesus went through in terms of making a suffering sacrifice, and thus it is appropriate that he held the attention of the priests by rehearsing the chapter in Isaiah that addresses the suffering of the servant of the Lord. Abinadi most likely recited Isaiah 53 from memory. It was a classic text. Abinadi may or may not have anticipated that the priests would turn to Isaiah 52, and he may well not have known that they were going to charge him with false prophecy. He likely had no time to prepare for this trial, and no defense lawyers were used in ancient Israelite criminal cases. He most likely had not anticipated that he would need to use Isaiah 53 in his defense, but he was prepared nonetheless.
Monte S. Nyman, "Abinadi’s Commentary on Isaiah," in The Book of Mormon: Mosiah, Salvation Only Through Christ, ed. Monte S. Nyman and Charles D. Tate, Jr. (Provo, UT: Religious Studies Center, Brigham Young University, 1991), 161–186.
Ann N. Madsen, "’What Meaneth the Words that Are Written?’ Abinadi Interprets Isaiah," Journal of Book of Mormon Studies 10, no. 1 (2001): 4–15.