Mormon 2:29

And the Lamanites did give unto us the land northward; yea, even to the narrow passage which led into the land southward. And we did give unto the Lamanites all the land southward.

The Lamanites gave us the land to the north. This went all the way to the narrow path that led to the land in the south. We gave the Lamanites all the land to the south.

The Lamanites gave us everything north of the narrow pass that led south. We gave them everything south of it.