Moroni's words in Mormon 9 stood out to me:
28 Be in the days of your ; strip yourselves of all uncleanness; ask not, that ye may consume it on your , but ask with a firmness unshaken, that ye will yield to no temptation, but that ye will serve the true and .
What is the opposite of stripping ourselves of uncleanness? Perhaps clothing ourselves with purity? Compare with the words of Jacob:
14 Wherefore, we shall have a of all our , and our , and our ; and the righteous shall have a perfect knowledge of their enjoyment, and their , being with , yea, even with the of righteousness. (2 Nephi 9)
This matches the language of the strong exhortation from Moroni to "those who do not believe in Christ" found at the beginning of Mormon 9:
1 And now, I speak also concerning those who do not believe in Christ.
2 Behold, will ye believe in the day of your visitation—behold, when the Lord shall come, yea, even that great day when the earth shall be rolled together as a scroll, and the elements shall melt with fervent heat, yea, in that great day when ye shall be brought to stand before the Lamb of God—then will ye say that there is no God?
3 Then will ye longer deny the Christ, or can ye behold the Lamb of God? Do ye suppose that ye shall dwell with him under a consciousness of your guilt? Do ye suppose that ye could be happy to dwell with that holy Being, when your souls are racked with a consciousness of guilt that ye have ever abused his laws?
4 Behold, I say unto you that ye would be more miserable to dwell with a holy and just God, under a consciousness of your filthiness before him, than ye would to dwell with the damned souls in hell.
5 For behold, when ye shall be brought to see your nakedness before God, and also the glory of God, and the holiness of Jesus Christ, it will kindle a flame of unquenchable fire upon you.
6 O then ye unbelieving, turn ye unto the Lord; cry mightily unto the Father in the name of Jesus, that perhaps ye may be found spotless, pure, fair, and white, having been cleansed by the blood of the Lamb, at that great and last day.
Notice that the solution for the unbelieving, offered in verse 6, involves "cry[ing] mightily unto the Father in the name of Jesus" -- an obvious reference to Priesthood ordinances -- as well as a description similar to that of the garments of the righteous from 2 Nephi 9:14 -- another obvious temple covenant reference.
In the outer court of the ancient temple, the rituals involved washing and cleansing to prepare to enter the holy place. In a similar fashion, in modern temples we change into white clothing. This corresponds to "strip[ping ourselves] of all uncleanness" and prepares us to be "clothed with purity, yea, even with the robe of righteousness."