Perhaps Enos turns to the topic of the Lamanites because it was the next possible choice. It is also probable that he does so because Jehovah has just said that the Nephites will have sorrow brought upon them. Perhaps that forlorn picture of the future of the Nephites led Enos to dream of hope in the redemption of the Lamanites.
An unusual technique that occurs from time to time in the Book of Mormon is the statement of the conclusion, prior to the details behind the conclusion. That is what we have in verse 12. That is the conclusion. Jehovah grants Enos’s request. We learn that—before we learn what the request was.
Enos does not pray for the salvation of the Nephites, for Jehovah had already declared their fate. What he does, however, is think about the records. He believes that the Lamanites might want to destroy them, and that perhaps they could be a future tool for the conversion of the Lamanites.
Why, however, would the Lamanites want to destroy the records? This would principally be the brass plates, which had probably become a symbol of Nephite legitimacy as a relic from the Old World, along with the Liahona and the sword of Laban. Those artifacts would be passed down to future kings as we will see with king Benjamin. Destroying the records would destroy a Nephite claim of superior right of rulership over the Lamanites.