Rav Yehuda said in the name of Shmuel, “Anyone who is not an expert in the laws of divorce and marriage should not be involved in them.”
Doesn’t marriage need to precede divorce chronologically? Why does this teaching mention divorce prior to mentioning marriage?
The laws of effecting a marriage are quite well-known compared to the great complexity of the laws of writing and giving a get for a divorce. In addition, in the event of error the potential consequences regarding the marriage of an unmarried woman are far less serious than those that could occur as a result of wrongly permitting a married woman to remarry. Therefore, although it is correct to only authorize rabbis who are familiar with the laws of kiddushin to perform marriage ceremonies, it is even more important to ensure that only the greatest halachic experts in the laws of gittin are allowed to deal with divorce matters.
In order to stress the greater caution required regarding divorce, the statement in our gemara mentions the laws of gittin before the laws of kiddushin. (Maharsha)
Wedding for a Widow
“Death (of her husband) is ‘equated’ with divorce; just as divorce permits her to remarry, likewise the death of her husband permits her to remarry.”
Rav Ashi offers this as a definitive proof for the halacha in the first Mishna of the Tractate, which teaches that a woman is permitted to marry another man if she is divorced or if her husband dies. The gemara on our daf asks for the source in the Torah from which we learn that a widow is permitted to remarry. The sugya offers numerous possible sources, but raises challenges to each attempted proof. This ‘equation’ between divorce and being widowed is unchallenged as a clear proof.
The verse where this equation, called a hekesh, is found is: “If the latter husband hates her and writes her a bill of divorce, and places it into her hand and sends her away from his house, or if the latter husband who took her as a wife dies, her first husband, who had sent her away, may not take her again to be his wife…” (Deut. 24:3-4)
Rashi asks why the gemara doesn’t prove that a widow may remarry from this same verse in a more direct manner. It states that if the second husband dies, her first husband may not remarry her, implying that she is, however, permitted to marry anyone else. Rashi answers that this proof could be rejected. Perhaps returning to her first husband would transgress a negative command, whereas marrying someone else would still violate a positive command. This is the same reasoning that the gemara used earlier to reject other suggested proofs to allow a widow to remarry.