What was Jesus Christ alluding to when He said the “fourth generation from this generation” of Nephites would sell Him for silver and gold?

According to one commentary, the Savior was saying, in essence: “This generation has seen and believed in the Atoning Messiah. Their faith will continue to be strong. But after four generations, their descendants will go astray. That apostasy again alludes to the Sermon at the Temple (3 Ne. 13:19). The Savior sorrowfully spells out the reason for their defection. It will be the same problem that has always plagued the Nephites—their desire for worldly status” (Gardner, Second Witness, 5:581–82).