Where There Is No Vision

Nephi made a rather strange statement in 1 Nephi 19:23.  He spoke of "those who are at Jerusalem" and then said, "For had not the Lord been merciful, to show unto me concerning them, even as he had prophets of old, I should have perished also."  What does he mean by that?  When did the Lord show unto Nephi a vision of those at Jerusalem, and why did that save his life?  It's possible that he was referring to the vision shown unto him by the angel wherein he recorded, "I looked and beheld the great city of Jerusalem, and also other cities. And I beheld the city of Nazareth; and in the city of Nazareth I beheld a virgin, and she was exceedingly fair and white" (1 Nephi 11:13).  He continued then to see the coming of the Savior and His ministry and atonement.  It's also likely that he had other visions of the people of Jerusalem, and perhaps he saw the same thing his father did concerning the destruction of Jerusalem: "I have seen a vision, in which I know that Jerusalem is destroyed;and had we remained in Jerusalem we should also have perished" (2 Nephi 1:4).  In either case, why would Nephi say that without such visions of Jerusalem and its people, "I should have perished"?  This reminds me of the verse in Proverbs: "Where there is no vision, the people perish" (Proverbs 29:18).  Perhaps it was the knowledge that he received from these visions of Jerusalem--the knowledge of the immediate destruction of its inhabitants as well as the knowledge of the coming of the Savior--that helped Nephi to persevere through the most difficult of challenges as they spent about a decade trying to travel to the promised land.  Nephi was certainly the glue that held the family together and provided the means for their journey's success, and perhaps he was suggesting here that it was the knowledge given him by the Lord that motivated him and helped him not to perish in the wilderness.  In a broader sense, we know that many "perish in the flesh because of unbelief" (2 Nephi 10:2). Nephi did not perish precisely because he believed and had great faith in the Lord, and that faith was strengthened because of the great things that the Lord showed him.