they should have save it were one wife, and concubines they should have none,

jacob 3  5 Behold, the Lamanites your brethren, whom ye hate because of their filthiness and the cursing which hath come upon their skins, are more righteous than you; for they have not ^aforgotten the commandment of the Lord, which was given unto our father—that they should have save it were ^bone wife, and ^cconcubines they should have none, and there should not be ^dwhoredoms committed among them.

6 And now, this commandment they observe to keep; wherefore, because of this observance, in keeping this commandment, the Lord God will not destroy them, but will be ^amerciful unto them; and one day they shall ^bbecome a blessed people.

a message from the book of mormon
mosiah 29
https://www.churchofjesuschrist.org/study/scriptures/bofm/mosiah/29?lang=eng