Taamei Hamitzvos - Returning a Divorcee
Mitzvah 580 — Devarim 24:1-4
If a divorced woman gets married to another man and then gets divorced again, she cannot remarry her first husband. The Torah explains that such a practice is abominable in Hashem’s eyes, and it could fill the land with sin. If it would be permitted, two men could divorce their wives temporarily with the intention of remarrying them after they have been married to the other man temporarily, thereby undermining the very foundation of marriage and the holiness of our nation.
Furthermore, if it were permitted to return a divorcee, it would be difficult to keep the Mitzvah not to covet the wife of another man who might be persuaded to relinquish his marital rights temporarily. Now that this is prohibited, and the only possibility of marriage to a married woman is through a permanent divorce, it is only natural not to covet something that in all likelihood will never become attainable (Moshav Zekeinim).
We may suggest a further reason: Without going into halachic details, the Sages prohibited a divorced couple from living in close proximity out of concern that their familiarity will lead to sin (Kiddushin 27b); thus we see that there is a greater concern regarding a previously married couple. In light of this, we may suggest that the Torah removed any possibility for a man to return his ex-wife once she has remarried so that his familiarity will not lead him to covet or transgress other prohibitions.
Lastly, the possibility of returning to the first husband could undermine the bond of the second marriage (see also Pesachim 112a). By completely severing the bond of the first marriage, the Torah grants the second marriage added strength and sanctity.
In Parashas Shemos, Amram married Yocheved after divorcing her, and, according to Targum Yonasan, after she had already gotten remarried to another man and divorced (Bamidbar 11:26). This was permitted because the Torah had not yet been given. Had the Torah already been given, Yocheved would have been prohibited to Amram on account of a more severe prohibition: she was his father’s sister. Although our ancestors strove to keep the Torah even before it was given, they sometimes determined it necessary to make exceptions. In this case, Amram determined that Yocheved was his designated wife, and only a woman as righteous as she would bear him children of great stature (Netziv to Shemos 6:20). Furthermore, none of the aforementioned reasons behind this Mitzvah applied in this case, as Amram was a completely righteous man who never committed a sin (Shabbos 55b), and he certainly did not divorce Yocheved with improper intentions.
As to why Hashem made it occur that a man as great as Moshe emerged from a union that He would later prohibit, Chizkuni explains (Shemos 6:20) that this served to humble Moshe. As the Sages teach, when electing a governor, choose someone who has a fault in his lineage so that the honor and authority of his position will not make him overly prideful (Yoma 22b).
