26 Again, we shall find on examination, that there is no opposition between the precept of the Lord about not putting away a wife, and what was said by them of old time: "Whosoever puts away his wife, let him give her a writing of divorcement." The Lord explains the intention of the law, which required a bill of divorce in every case where a wife was put away. The precept not to put away a wife is the opposite of saying that a man may put away his wife if he pleases; which is not what the law says.
On the contrary, to prevent the wife from being put away, the law required this intermediate step, that the eagerness for separation might be checked by the writing of the bill, and the man might have time to think of the evil of putting away his wife; especially since, as it is said, among the Hebrews it was unlawful for any but the scribes to write Hebrew: for the scribes claimed the possession of superior wisdom; and if they were men of upright and pious character, their pursuits might justly entitle them to make this claim.
In requiring, therefore, that in putting away his wife, a man should give her a writing of divorcement, the design was that he should be obliged to have recourse to those from whom he might expect to receive a cautious interpretation of the law, and suitable advice against separation. Having no other way of getting the bill written, the man should be obliged to submit to their direction, and to allow of their endeavors to restore peace and harmony between him and his wife. In a case where the hatred could not be overcome or checked, the bill would of course be written.
A wife might with reason be put away when wise counsel failed to restore the proper feeling and affection in the mind of her husband. If the wife is not loved, she is to be put away. And that she may not be put away, it is the husband's duty to love her. Now, while a man cannot be forced to love against his will, he may be influenced by advice and persuasion. This was the duty of the scribe, as a wise and upright man; and the law gave him the opportunity, by requiring the husband in all cases of quarrel to go to him, to get the bill of divorcement written.
No good or prudent man would write the bill unless it were a case of such obstinate aversion as to make reconciliation impossible. But according to your impious notions, there can be nothing in putting away a wife; for matrimony, according to you, is a criminal indulgence. The word "matrimony" shows that a man takes a wife in order that she may become a mother, which would be an evil in your estimation. According to you, this would imply that part of your god is overcome and captured by the race of darkness, and bound in the fetters of flesh.
Source: Reply to Faustus the Manichaean (New Advent)