Borrowed authority

This must be early in Jacob’s time as a spiritual leader of the people. He leans on the authority of Nephi because the people respect and trust Nephi so he indicates that neigh wanted him to share this message. He also leans on the authority of Isaiah by quoting from Isaiah but I hadn’t realized before that only a little bit of what he says here is writing Isaiah while most of it is expounding on what Isaiah prophesied.

Part of this pattern of leaning on the authority of someone else might also be cultural—it is common within the Jewish tradition to base your statements on the words of established authority figures.