Doctrine and Covenants 113 explains that the phrase “put on thy strength” means that latter-day priesthood holders will “put on the authority of the priesthood, which [they have] a right to by lineage” (D&C 113:7–8). “The bands of [thy] neck are the curses of God upon her, or the remnants of Israel in their scattered condition among the Gentiles” (D&C 113:10).
Speaking of the eventual movement toward the millennial era, Elder Bruce R. McConkie explained the Savior’s words: “We have already seen that Jesus put chapter 52 of Isaiah in a millennial context. In it is found the cry: ‘Awake, awake; put on thy strength, O Zion; put on thy beautiful garments, O Jerusalem, the holy city: for henceforth there shall no more come into thee the uncircumcised and the unclean.’ In the day of which we speak there will be none who are unclean in the telestial sense of the word, for the wicked will be destroyed by the brightness of His coming. And there will be none who are uncircumcised, as it were, for all who seek the blessings of the Holy City will be in harmony with the plans and purposes of Him whose city it is” (Millennial Messiah, 315).