It would seem that in the Old Testament God sanctioned polygamy. Not so. Jesus said that in the beginning “the two shall become one flesh” (Matt. 19:4,5). He did not say “the fifteen shall become one flesh.” God gave Israel kings, but that was His permissive not His perfect will. Polygamy is in the same category.
2 Chronicles 13:21 But Abijah grew mighty, married fourteen wives, and begot twenty-two sons and sixteen daughters.