Since we are in the time between Passover and Shavuot, I figured it would be appropriate to discuss, albeit briefly, a couple of texts discussing this time period:
The first of these is what Rabbi Yaakov, son of Asher wrote, in his famous halakhic work, regarding customs of what to do during the period between Passover and Shavuos (Tur, Orah Hayyim §492):
נוהגין בכל המקומות שלא לישא אשה בין פסח לעצרת והטעם שלא להרבות בשמחה שבאותו זמן מתו תלמידי ר"ע וכתב הר"י גיאת דוקא נישואין שהוא עיקר שמחה אבל לארס ולקדש שפיר דמי ונישואין נמי מי שקפץ וכנס אין עונשין אותו אבל אם בא לעשות בתחלה אין מורין לו לעשות כך וכזה הורו הגאוני' ויש מקומות שנהגו שלא להסתפר ויש מסתפרי' מל"ג בעומר ואילך שאומרים שאז פסקו מלמות מצאתי כתוב מנהג שלא לעשות מלאכה מפסח ועד עצרת משקיעת החמה עד שחרית משום תלמידי רבי עקיבא שמתו סמוך לשקיעת החמה ונקברו אחר שקיעת החמה והיה העם בטלין ממלאכה על כן גזרו שלא לעשות שמחה בינתיים ונהגו הנשים שלא לעשות מלאכה משתשקע החמה ועוד שאנו סופרים העומר אחר שקיעת החמה וכתיב שבע שבתות תמימות תהיינה מלשון שבות ולשון שמיטה שבע שבתות וכתיב וספרת לך שבע שבתות שנים מכאן שהספירה כבית דין מה שנת השמיטה אסור במלאכה אף זמן ספירת העומר דהיינו לאחר שקיעת החמה אסור במלאכה
There are many places that are accustomed not to marry between Passover and Shavuot. The reason is in order to not increase in merriment, for at that time, Rabbi Akiva’s students died. Rabbi Isaac ibn Ghiyyat wrote it is specifically marriage, which is the main aspect of merriment, but to engage or betroth are quite alright. And marriage, also, for whom he leaps and brings her in – we do not punish him. But if he came to do it initially, we do not advise him to do as such. And, like this, the Geonim taught.
And there are places who are accustomed to not cut their hair. And there are those who cut their hair from the 33rd day of the omer and thenceforth, for they say that that is when they ceased from dying.
I found a custom written down to not do creative work from Passover until Shavuot from sunset until the morning prayer service, on account of Rabbi Akiva’s students who died close to sunset and were buried after sunset and the nation desisted from working. Therefore, they decreed not to make merriment between them.
And women are accustomed to not work from sunset.
Furthermore, we count the omer after sunset. And it is written, “Seven complete weeks it shall be” from the language of resting and the language of laying fallow seven weeks. And it is written, “And you shall count for yourself seven weeks of years.” From here, the counting is like the court: just as the year of laying fallow, work is forbidden, so, too, the time of the counting of the omer, which is after sunset, work is forbidden.
Regarding the origin of the tradition regarding Rabbi Akiva’s students dying (presumably early second century) is found in the Talmud as follows (Yevamos 62b):
דתניא, רבי יהושע אומר: נשא אדם אשה בילדותו - ישא אשה בזקנותו, היו לו בנים בילדותו - יהיו לו בנים בזקנותו, שנא': +קהלת י"א+ בבקר זרע את זרעך ולערב אל תנח ידך כי אינך יודע אי זה יכשר הזה או זה ואם שניהם כאחד טובים;
ר"ע אומר: למד תורה בילדותו - ילמוד תורה בזקנותו, היו לו תלמידים בילדותו - יהיו לו תלמידים בזקנותו, שנא': בבקר זרע את זרעך וגו'.
אמרו: שנים עשר אלף זוגים תלמידים היו לו לרבי עקיבא, מגבת עד אנטיפרס, וכולן מתו בפרק אחד מפני שלא נהגו כבוד זה לזה, והיה העולם שמם, עד שבא ר"ע אצל רבותינו שבדרום, ושנאה להם ר"מ ור' יהודה ור' יוסי ורבי שמעון ורבי אלעזר בן שמוע, והם הם העמידו תורה אותה שעה.
It was taught:
Rabbi Yehoshua says, “If a man married a woman in his youth, he should marry in his older age. If he had children in his youth, he should have children in his older age, as it is said, ‘In the morning, plant your seed; and in the evening, do not let your hand rest, because you do not know which one will prosper – this one or this one, or if both of them will be good like one.’”
Rabbi Akiva says, “If he learned Torah in his youth, he should learn Torah in his older age. If he had students in his youth, he should have students in his older age, as it is said, ‘In the morning, plant your seed; and in the evening, do not let your hand rest, because you do not know which one will prosper – this one or this one, or if both of them will be good like one.’”
They said, “Rabbi Akiva had 12,000 pairs of students, geographically ranging from Gabbatha until Antipatris – and they all died at one segment of time, because they did not accord honor one to the other. And the world was desolate until Rabbi Akiva reached our rabbis in the south and taught the Torah to them. They were Rabbi Meir, Rabbi Yehudah, Rabbi Yosé, Rabbi Shim’on, and Rabbi Eleazar, son of Shammua, and they revived the Torah at that time."
After the latter part of this tannaitic text, the editor places next to this text another tannaitic text, specifying the time period of when their collective death occurred:
תנא: כולם מתו מפסח ועד עצרת.
It was taught: All of them died from Passover until Shavuot.
Following these tannaitic statements, a further specification about what occurred is stated by either the third century sage, Rav Hama, son of Abba, or the fourth century sage, Rabbi Hiyya, son of Avin:
אמר רב חמא בר אבא, ואיתימא ר' חייא בר אבין: כולם מתו מיתה רעה.
Rav Hama, son of Abba or maybe Rabbi Hiyya, son of Avin, said, “All of them died a terrible death.”
After which, the Talmud's editor inserts "מאי היא? - which death was it that was so bad?" in order to set up the statement by Rav Nahman, the turn-of-the-fourth century sage, identifying it as "אסכרה -It was croup.”
Reflecting back to what Rabbi Ya'akov, son of Asher wrote, we can understand why the keyword in this section is "accustomed" - as the Talmud records no actions to do during this time (aside from counting the omer) and everything regarding this period is post-Talmudic custom.
(I hope to return to this topic a little bit more in depth....)