The rest of chapter 20 contains some quotation and explanation of what Jehovah (Jesus) had revealed centuries earlier to Isaiah, as recorded in Isaiah 52—the most frequently cited chapter of Isaiah in the Book of Mormon (see also 2 Nephi 8:24–25; Mosiah 12:20–24; 15:13–18; Moroni 10:31).
Jesus again encourages his faithful ones to search the writings of Isaiah and to notice that when his prophecies are fulfilled, they will know that the Father’s covenants to all Israel—including them—are being fulfilled.
Isaiah’s prophecies include a great gathering to lands of inheritance—including Lehi’s posterity in the Americas—and a gathering to the knowledge of the Lord their God.