Notice how the citation from Isaiah is bracketed in Abinadi’s argument:
Have they not said that God himself should come down among the children of men, and take upon him the form of man, and go forth in mighty power upon the face of the earth? Yea, and have they not said also that he should bring to pass the resurrection of the dead, and that he, himself, should be oppressed and afflicted? (Mosiah 13:34–35)
The quotation of Isaiah 53:1–12, constitutes Mosiah 14 .
And now Abinadi said unto them: I would that ye should understand that God himself shall come down among the children of men, and shall redeem his people. (Mosiah 15:1)
Both leading into and coming out of the Isaiah proof text, Abinadi’s message is that “God [Yahweh] himself” will come down and effect the atonement. While most LDS commentaries remain relatively silent on the phrase “God himself,” that is nevertheless the driving point behind Abinadi’s entire argument. This phrasing is part of his counter-attack on the priests of Noah, particularly his discussion of the commandment to have no other gods. (See commentary accompanying Mosiah 12:35–37.)
Abinadi is facing priests who deny the Atoning Messiah while claiming to believe in the law of Moses. Abinadi is using that law against them, turning their assumptions back on them. While they assume that they have no other gods, Abinadi is showing them that they have essentially created a new god because they deny the revealed traits of the God of Moses.
For latter-day readers, this verse and the next few present some theological confusion because of Abinadi’s apparent conflation of Jesus and God. The Nephite understanding was that the Jehovah would come to earth as the Messiah. Modern readers read “Jehovah” as the premortal designation for Christ, and, hence, agree with the Nephites. (See “Excursus: The Nephite Understanding of God,” following 1 Nephi 11 for more information on Yahweh as Father.)
Rhetoric: It is tempting to characterize Abinadi’s use of Isaiah 53 as a commentary. It is not. Abinadi paraphrases and expands Isaiah. He uses the Isaiah text as his base, returning to it more frequently than Nephi and Jacob did when they used Isaiah. Abinadi uses Isaiah to further his own arguments; he does not explain Isaiah so that it may be understood.