Mosiah 10:17

And thus they have taught their children, that they should hate them, and that they should murder them, and that they should rob and plunder them, and do all they could to destroy them; therefore, they have an eternal hatred towards the children of Nephi.

So they taught their children to hate Nephi’s people. They taught them to kill, steal from, and hurt them. They taught them to do everything they could to destroy them. So they will always hate Nephi’s children.

That’s what they’ve taught their children—to hate us, to murder us, to rob and destroy us in every way they can. So they have this never-ending hatred toward Nephi’s descendants.