(Isa. 48:12; 41:4; 44:6; Rev. 22:13; Alma 11:39; D&C 110:4; Heb. 12:2)
These words express the eternal nature of the Lord Jesus Christ … Jesus was the first to be born in the spirit. He is the first in position and dominion. He is the last in that he will continue as God, preeminent over all, through all eternity. Jesus is also the first and the last in that he is both the “author and finisher of our faith” (Heb. 12:2).
(Donald W. Parry, Jay A. Parry, and Tina M. Peterson, Understanding Isaiah [Salt Lake City: Deseret Book Co., 1998], 418.)