I actually do not see any Biblical restriction on polygamy. In fact, the original interpretation was that you could have as many wives (and in a modern day and age of egalitarianism, husbands) as you can financially and emotionally take care of. In Ashkenazi Jewery there was a cherem (that is decree that one would be excommunicated) if one took more than one wife, but the time period it was covering has already elapsed without official renewal, and was started in my opinion, to bow to the requirements of the Christian West in which those Jews were living, which officially forbade anything but monogamy. There were actually many Christian sects which forbade marriage and sex altogether as Christianity began as a millenial religion that posited that the end of the world had arrived. And that is not to dis anyone who is Christian, because there are good points to that religion too, but that is history as I see it.