In the movie “The Paper Chase,” a Harvard student rips out a page of the law report so that his fellow student will be unable to read it and will come to the lecture unprepared. About 2,000 years earlier a student lay feverishly ill in the academy of Rabbi Akiva in Bnei Brak. So caught up were the other students in the competitiveness of their learning that they found no time to visit him or take care of him. As the student lay dying, Rabbi Akiva himself entered the sick room, fed him, made him comfortable and swept the dust from the floor. The sick student survived. His peers did not.
Between Pesach and Shavuot, 24,000 of them died from diphtheria because they acted inconsiderately to one another. According to other sources, the students of Rabbi Akiva were massacred by the Romans after the murder of Rabbi Akiva himself. This was because they taught Torah in public, in violation of the Roman decree that forbade the study of all sacred texts.
The behavior of Rabbi Akiva’s students left them particulary vulnerable betweeen Pesach and Shavuot since this period is a time of celestial judgment. Furthermore, as Rabbi Goren points out, the Oral Torah, like the written Torah, could only be given when the Jews lived together in harmony. Accordingly, Rabbi Akiva’s students were not worthy of being the teachers of the Oral Law. The death of so many of Rabbi Akiva’s disciples threatened the very survival of the Oral Law. Only a few students survived to become the standard bearers of tradition. They were Rabbi Meir, Rabbi Yehuda, Rabbi Yose, Rabbi Shimon Bar Yochai and Rabbi Elazar Ben Shamua.
To commemorate this sad event, it has long been the custom to adopt certain forms of mourning on the days the students died. There is, however, a difference of opinion as to when the deaths occurred. According to the opinion of the Shulchan Aruch, they died during the 34 days immediately following Pesach, including the day of and the day following Lag B’Omer. Accordingly, one mourns for them from Pesach until daybreak following the day of Lag B’Omer. The Rema points out that because of the festivities of Lag B’Omer, all forms of mourning cease on Lag B’Omer itself.
As is usually the case, people of Sephardi origin follow the ruling of the Shulchan Aruch and do not shave or arrange weddings on Lag B’Omer. People of Ashkenazi origin do shave and arrange weddings on Lag B’Omer. Rav Ovadia Yosef rules that the authorities in Israel must determine the Sephardi or Ashkenazi origin of the couple before registering them for marriage on Lag B’Omer. In cases where the groom is Ashkenazi and the bride is Sephardi or vice versa, the custom of the groom is followed.
The second opinion is that of Tosafot. According to this opinion, no deaths occurred on the 16 days between Pesach and Shavuot, when Tachanun is not recited. Accordingly, there should be no mourning on the seven days of Pesach, the six days of Shabbat, the two days of Rosh Chodesh Iyar and on the day of Rosh Chodesh Sivan. According to the opinion of Tosafot, the thirty-three days of mourning commence only after Pesach and because there is no mourning on the sixteen days indicated, the mourning ends on Erev Shavuot.
Rabbi Moshe Feinstein points out that there are an additional three variations on the first opinion and one variation on the opinion of Tosafot, namely that of the Ari, who mourned for the students from Pesach through to Shavuot without any break. The period of mourning that one observes depends on the custom of the community to which one belongs.
The forms of mourning that are observed are not shaving, not taking a haircut, not attending weddings and not listening to music. According to one opinion, one may listen to recorded music when Jewish music with words from the scriptures is being played. In former times, people would also cease all work after nightfall in commemoration of the funerals of the students that took place at night. Engagements and engagement parties are permitted during the sefirah period. The mohel, the father of the child and the sandek may shave in honor of a brit ceremony during the sefirah period.