Jacob's prophecy

I haven't really noticed this prophecy by Jacob before:

And the time speedily cometh, that except ye repent they [the Lamanites] shall possess the land of your inheritance, and the Lord God will lead away the righteous out from among you. (Jacob 3:4)

We read in 2 Nephi 5, that Nephi and those who wanted to come with him separated from his older brothers and they beame Nephites and Lamanites.

And my people would that we should call the name of the place Nephi; wherefore, we did call it Nephi. (2 Nephi 5:8)

The Nephites lived in the land/city of Nephi for about 350-400 years, until Omni 1:12-13

Behold, I will speak unto you somewhat concerning Mosiah, who was made king over the land of Zarahemla; for behold, he being warned of the Lord that he should flee out of the land of Nephi, and as many as would hearken unto the voice of the Lord should also depart out of the land with him, into the wilderness—

And it came to pass that he did according as the Lord had commanded him. And they departed out of the land into the wilderness, as many as would hearken unto the voice of the Lord; and they were led by many preachings and prophesyings. And they were admonished continually by the word of God; and they were led by the power of his arm, through the wilderness until they came down into the land which is called the land of Zarahemla.

This is the fulfillment of Jacob 3:4. The righteous Nephites fled out of the land of Nephi and Zarahemla now became their new capital. The other part of Jacob's prophecy was that the Lamanites should possess the land of Nephi. Most likely, when the righteous Nephites fled, the remaining wicked Nephites were destroyed by the Lamanites who took their lands in possession. In Mosiah 9, Zeniff is in Zarahemla but is eager to go and live in the land of Nephi

I, Zeniff, having been taught in all the language of the Nephites, and having had a knowledge of the land of Nephi, or of the land of our fathers’ first inheritance

When Zeniff gets there, the land is possessed by Lamanites, demonstrating that this part of Jacob's prophecy also had been fulfilled. Mosiah 9 also talks about the land, "Lehi-Nephi" which I presume to mean the larger area where both the Nephites and Lamanites used to live. That is, when they arrived in the promised land, it was called Lehi. The Lamanites stayed there, while Nephi and his people separated and lived in the land, Nephi.

As usual, this is not straight forward, but internally consistent.