As Jesus begins this discourse on the gathering and redemption of Israel, he does so by specifically referencing Isaiah, and noting that the people have those words, and that they should search them. In this particular context, the Savior is suggesting that Isaiah contains information on the gathering of Israel that would be of importance to them. Indeed, during this discourse, he does cite virtually all of Isaiah 52. He had cited the text as a whole on the previous day (3 Nephi 16:18-20) and will make the assumption that his audience will recognize the separate verses. As the discourse continues, the Savior will interweave commentary and scriptural text.
Translation: References to searching scriptures certainly have an independent meaning, but the phrases itself comes from the KJV version of John 5:39: “Search ye the scriptures…” While that imperative in the Johnannine context was particularly aimed as those who searched but did not understand, the command to all of us to search them still stands. Of course, it is best to search with true understanding. That comes from the restoration of the gospel and the continual guidance of the Lord’s prophets.