This coming week we will be celebrating the holiday of Lag Ba'Omer, a festive day situated in the seven mournful weeks, in which we count the Omer. The two main explanations for why we celebrate this unique holiday are that it is the day that Rabi Akiva’s students stopped dying, and that it is the Azkarah/Yahrtzeit of Rabi Shimon Bar Yochai.
With regards to the first explanation, the Gemara Yevamot (62b) states that Rabi Akiva’s students died in the weeks spanning Pesach and Shavuot, but the Gemara never mentions Lag Ba’Omer. The simple reading of the Gemara is that all of his students died by Shavuot, so why do we celebrate on Lag Ba’Omer? Furthermore, if this was such a great tragedy, why do we celebrate at all?
The Me’iri and the Ba’al HaMa’or were the earliest Halachic authorities to make any mention of Lag Ba’Omer. The Me’iri records a tradition from the Ge’onim that Rabi Akiva’s students stopped dying on the thirty third day of the Omer, contrary to the simple understanding of the Gemara. The Sefer HaManhig states, citing the Ba'al HaMa’or, that one can marry on the thirty third day of the Omer, unlike the previous days of the Omer, since they are days of mourning. According to the Ba’al HaMa’or, the thirty third day of the Omer’s only significance is that it is the conclusion of a period of mourning.
The Maharil, however, cites a statement of the Mahari Segal that claims that Rabi Akiva’s Talmidim actually died over a span of 33 days between Pesach and Shavuot. So Lag Ba'Omer is a commemoration of the day on which the plague that killed so many students finally ended.
There is debate, however, on when this span of thirty three days actually occurred. If the Talmidim died within the first thirty three days of the Omer, then that should be the mourning period as well. But if they died during any segment of thirty three days throughout the forty nine days of the Omer, then the period of mourning does not necessarily start at the onset of the Omer. The Rama (O.C. 493:3) states that the mourning period should begin on Rosh Chodesh Iyar and continue until three days before Shavuot.
Let us now examine Lag Ba'Omer as the Yahrzeit of Rabi Shimon Bar Yochai. The Ateret Zekeinim (O.C. 493) writes that there is a custom to pray and learn at Rabi Shimon Bar Yochai’s grave in Meiron on Lag Ba’Omer. Both the Chatam Sofer (Y.D. 233) and the Sho'el U'Meishiv (5:39) opposed the custom of Lag Ba'Omer commemorating the Yahrzeit of Rabi Shimon Bar Yochai; they claimed that in order to make a holiday there needs to be precedence in Tanach or a miracle needs to happen, and a Yahrzeit does not comply with these criteria. Especially since a Yahrzeit should be a day of mourning, not a holiday. The Shulchan Aruch (O.C. 568:8-9) even states that one should fast on their father’s Yahrtzeit. The Sheim Aryeh (O.C. 14) offers a rebuttal to the Chatam Sofer and the Sho'el U'Meishiv, claiming that Rabi Shimon Bar Yochai’s existence was miraculous. Throughout his life, Rabi Shimon bar Yochai was persecuted by the Roman government, therefore, living a full life and dying peacefully were miracles.
Both of these explanations seem to justify why Lag Ba'Omer should be a synthesis of a festivity and mourning, but they does not explain why we still celebrate it today. An answer might be found by contrasting the Talmidim of Rabi Akiva and Rabi Shimon Bar Yochai. The Gemara Yevamot (62b) states that Rabi Akiva’s Talmidim died because they did not treat each other with respect. On the other hand, Rabi Shimon Bar Yochai (Pirkei Avot 6:8) lists several qualities that are befitting of a Tzaddik (righteous person) and the rest of the world. One of the enumerated qualities is honor; he believes that everyone should be treated in a respectful, honorable manner. The Talmidim of Rabi Akiva, however, failed to recognize the importance of treating others with respect. On Lag Ba’Omer we remember this message of Rabi Shimon Bar Yochai, in contrast to the Talmidim of Rabi Akiva, that we should always treat our peers with the utmost respect.