8 So manifold being the vices and so great the ignominies with which marriage was defiled, an alleviation and a remedy were at length bestowed from on high. Jesus Christ, who restored our human dignity and who perfected the Mosaic law, applied early in His ministry no little solicitude to the question of marriage. He ennobled the marriage in Cana of Galilee by His presence, and made it memorable by the first of the miracles which he wrought;(7) and for this reason, even from that day forth, it seemed as if the beginning of new holiness had been conferred on human marriages. Later on He brought back matrimony to the nobility of its primeval origin by condemning the customs of the Jews in their abuse of the plurality of wives and of the power of giving bills of divorce; and still more by commanding most strictly that no one should dare to dissolve that union which God Himself had sanctioned by a bond perpetual. Hence, having set aside the difficulties which were adduced from the law of Moses, He, in character of supreme Lawgiver, decreed as follows concerning husbands and wives, "I say to you, that whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery; and he that shall marry her that is put away committeth adultery."(8)
Source: Arcanum Divinae (Vatican.va)