Jacob now launches into the longest single chapter in the entire Book of Mormon. It is a quotation from the writings of the prophet Zenos. This great prophet was a descendant of Joseph and he was slain for telling the Israelites that when the Messiah came among them they would mistake him for an imposter and crucify him.
We do not know the exact date of the ministry of Zenos, but we do know how the writings of this great prophet came into the possession of the Nephites. It will be recalled that the Nephites possessed the brass plates which had been brought from Jerusalem. This treasure of scripture contained the writings of the prophets clear back to the Creation and contained a number of books which are not found in the modern Bible. The writings of Zenos are among the books missing from the Bible, and we are therefore extremely fortunate to have this chapter of Zenos included in the writings of Jacob in the Book of Mormon.
This chapter has to do with the famous allegory of the tame olive tree. An allegory is a parable, and you have to have a key to interpret it or it is meaningless. The allegory of the tame olive tree constitutes a prophetic history of mankind covering a period of approximately 3,000 years. Most of it has already come to pass, so we find the key to its meaning in the unfolding of human history.
Zenos pleaded with the house of Israel to listen to his words because he was going to speak to them as a prophet of the Lord. In other words, this was not wishful thinking or the figment of a poetic literary imagination, but a revelation from God depicting the future history of Israel in a parable. The Lord had said to Zenos that he would liken the house of Israel to a tame olive tree. He said this tree had been carefully nourished and cultivated, and then it began to be old and started to decay.