THE BOOK OF JACOB
THE BROTHER OF NEPHICHAPTER 2:27Wherefore, my brethren, hear me, and hearken to the word of the Lord:For there shall not any man among you have save it be one wife; and concubines he shall have none;
And HERE we have the FairMormon spin applied:
http://www.fairmormon.org/perspectives/publications/contradiction_between_jacob_and_dc_132