Nor do I wish to pass over in silence the abominable authorization given by your legislator to have with your wives a commerce that he has compared, I am ashamed to say, to the tilling of fields. As a consequence of this license, a a goodly number of you have contracted the habit of multiplying their commerce with women, as if it were a question of tilling fields. Nor can I forget the chastity of your Prophet and the manner full of artifice whereby he succeeded in seducing the woman Zeda [sic, Zaynab; see Koran 33:37– 38; see further elaboration from the hadith, and jurisprudence, etc. here and here]. Of all these abominations the worst is that of accusing God of being the originator of all these filthy acts, which fact has doubtless been the cause of the introduction of this disgusting law. Is there indeed a worse blasphemy than that of alleging that God is the cause of all this evil?…[F]or I know nothing worse than not holding sin to be such as it is, and that is what you really do in never seeking nor receiving pardon [see Koran 14:4]. In the Gospel God has commanded the husband not to repudiate the wife save for the cause of adultery, but you act otherwise. When you are tired of your wives, as of some kind of nourishment, you abandon them at your fancy. It had been my intention to conceal, if possible the shamelessness with which you remarry, and how before retaking your repudiated wives you make them sleep in the bed of another. [Koran 2:227– 2:232] And what shall I say of the execrable debauchery which you commit with your concubines? For you are prodigal with them of all your fortune, and then, when you are tired of them you sell them like cattle [Koran 4:3; 4:24– 25; 23:6]
— Letter from Leo III to Caliph Umar II
Source: Leo III’s 1300-Year-Old Lesson: Understand Islam to Defeat Jihad
