Matthew 5:31

It hath been said. — The better MSS. give, “But it was said,” as though stating an implied objection to the previous teaching. Men might think that they could avoid the sin of adultery by taking the easy course of divorcing one wife before marrying another.

Whosoever shall put away... — The quotation is given as the popular Rabbinic explanation of Deuteronomy 24:1, which, as our Lord teaches in Matthew 19:8, was given, on account of the hardness of men’s hearts, to prevent yet greater evils. The words of the precept were vague — “If she find no favour in his eyes, because he hath found some uncleanness in her,” and the two school of casuists took opposite views of its meaning. The stricter party of Shammai held that the “uncleanness” meant simply unchastity before or after marriage. The followers of Hillel held, on the other hand (as Milton among Christian teachers), that anything that made the company of the wife distasteful was a sufficient ground for repudiation. Even a moralist generally so pure and noble as the son of Sirach, took in this matter the laxer view — “If she go not as thou wouldest have her, cut her off from thy flesh, and give her a bill of divorce, and let her go” (Sir. 25:26). It is noteworthy that our Lord, whose teaching, especially as regards the Sabbath question, might have been, for the most part, claimed by the school of Hillel, on this matter of divorce stamps the impress of His approval on the teaching of his rival.