Mormon 5:9

and also that a knowledge of these things must come unto the remnant of these people, and also unto the Gentiles, which the Lord hath said should scatter this people, and this people should be counted as nought among them, therefore I write a small abridgement, daring not to give a full account of the things which I have seen, because of the commandment which I have received, and also that ye might not have too great sorrow because of the wickedness of this people.

These people’s children must know about this. The Gentiles must know too. The Lord said the Gentiles would scatter this people. This people would be counted as nothing by them. So I’m writing a short summary. I won’t give a full account of what I saw. This is what God told me to do. Also, I don’t want you to be too sad about how bad this people was.

The survivors of this people need to know what happened here. So do the Gentiles, who the Lord said would scatter this people and treat them as nothing. That’s why I’m writing this short account. I won’t give you everything I’ve seen—partly because I’ve been commanded not to, and partly to spare you the full weight of grief over how wicked these people became.