In a letter addressed to Joseph Levin Metzsch of December 9, 1526, Luther says:  “Your first question:  Whether person may have more than one wife?  I answer thus:  Let unbelievers do what they please; Christian liberty, however, is regulated by love (charity), so that all that a Christian does is done to serve his fellow-man, provided only that he can render such service without jeopardy and damage to his faith and conscience.  Nowadays, however, everybody is striving for a liberty that profits and pleases him, without regard for the profit and improvement which his neighbor might derive from his action.  This is contrary to the teaching of St. Paul, who says:  ’All things are lawful unto me, but all things are not expedient’ (1 Cor. 6, 12).  Only see that your liberty does not become an occasion to the flesh. . . .  Moreover, although the patriarchs had many wives, Christians may not follow their example, because there is no necessity for doing this, no improvement is obtained thereby, and, especially, there is no word of God to justify this practise, while great offense and trouble may come from it.  Accordingly, I do not believe that Christians any longer have this liberty.  God would have to publish a command that would declare such a liberty.” (21a, 901 f.) To Clemens Ursinus, pastor at Bruck, Luther writes under date of March 21, 1527:  “Polygamy, which in former times was permitted to the Jews and Gentiles, cannot be honestly approved of among Christians, and cannot be engaged in with a good conscience, unless in an extreme case of necessity, as, for instance, when one of the spouses is separated from the other by leprosy or for a similar cause.  Accordingly, you may say to the carnal people (with whom you have to do), if they want to be Christians, they must keep married fidelity and bridle their flesh, not give it license.  If they want to be heathen, let them do what they please, at their own risk.” (21a, 928.)

In his comment on the question of the Pharisees regarding divorce (Matt. 19, 3-6), Luther says:  “Many divorces occur still among the Turks.  If a wife does not yield to the husband, nor act according to his whim and fancy, he forthwith drives her out of the house, and takes one, two, three, or four additional wives, and defends his action by appealing to Moses.  They have taken out of Moses such things as please them and pander to their lust.  In Turkey they are very cruel to women; any woman that will not submit is cast aside.  They toy with their women like a dog with a rag.  When they are weary of one woman, they quickly put her beneath the turf and take another.  Moses has said nothing to justify this practise.  My opinion is that there is no real married life among the Turks; theirs is a whorish life.  It is a terrible tyranny, all the more to be regretted because God does not withhold the common blessing from their intercourse:  children are procreated thereby, and yet the mother is sent away by the husband.  For this reason there is no true matrimony among the Turks.  In my opinion, all the Turks at the present time are bastards.” (7, 965.)