TL;DR - Lag b'Omer is the 33rd day of the Omer (The Hebrew letters lamed and gimel which make up the acronym “Lag” have the combined numerical value of 33).
WHY IS THIS SIGNIFICANT?
The Omer, which represents the time between Pesach and Shavuout is typically a period of semi-mourning and solemnity (she's giving Elul vibes). We are preparing to receive the Torah at Sinai, so this is the time to prep your soul to make sure we are fully ready and taking this seriously. During this time, traditional Jews do not celebrate weddings or get haircuts--anything that can indicate pure joy ... EXCEPT on Lag b'Omer.
SO WHY IS THIS DAY DIFFERENT FROM ALL OTHER (OMER) DAYS?
According to a medieval tradition, the plague ceased on Lag Ba’omer, the 33rd day of the Omer. As a result, Lag Ba’omer became a happy day, interrupting the sadness of the Omer period for 24 hours.
Source: My Jewish Learning

DISCUSSION QUESTIONS:
1. What did the story of Rabbi Akiva's students evoke for you?
2. What other aspects of our text and tradition does it remind you of?
(ז) וַיְדַבֵּ֥ר יְהֹוָ֖ה אֶל־מֹשֶׁ֑ה לֶךְ־רֵ֕ד כִּ֚י שִׁחֵ֣ת עַמְּךָ֔ אֲשֶׁ֥ר הֶעֱלֵ֖יתָ מֵאֶ֥רֶץ מִצְרָֽיִם׃ (ח) סָ֣רוּ מַהֵ֗ר מִן־הַדֶּ֙רֶךְ֙ אֲשֶׁ֣ר צִוִּיתִ֔ם עָשׂ֣וּ לָהֶ֔ם עֵ֖גֶל מַסֵּכָ֑ה וַיִּשְׁתַּֽחֲווּ־לוֹ֙ וַיִּזְבְּחוּ־ל֔וֹ וַיֹּ֣אמְר֔וּ אֵ֤לֶּה אֱלֹהֶ֙יךָ֙ יִשְׂרָאֵ֔ל אֲשֶׁ֥ר הֶֽעֱל֖וּךָ מֵאֶ֥רֶץ מִצְרָֽיִם׃ (ט) וַיֹּ֥אמֶר יְהֹוָ֖ה אֶל־מֹשֶׁ֑ה רָאִ֙יתִי֙ אֶת־הָעָ֣ם הַזֶּ֔ה וְהִנֵּ֥ה עַם־קְשֵׁה־עֹ֖רֶף הֽוּא׃ (י) וְעַתָּה֙ הַנִּ֣יחָה לִּ֔י וְיִֽחַר־אַפִּ֥י בָהֶ֖ם וַאֲכַלֵּ֑ם וְאֶֽעֱשֶׂ֥ה אוֹתְךָ֖ לְג֥וֹי גָּדֽוֹל׃
(1) When the people saw that Moses was so long in coming down from the mountain, the people gathered against Aaron and said to him, “Come, make us a god who shall go before us, for that fellow Moses—the man who brought us from the land of Egypt—we do not know what has happened to him.” (2) Aaron said to them, “[You men,] take off the gold rings that are on the ears of your wives, your sons, and your daughters, and bring them to me.” (3) And all the people took off the gold rings that were in their ears and brought them to Aaron. (4) This he took from them and cast in a mold,*cast in a mold Cf. Zech. 11.13 (beth hayyoṣer, “foundry”); others “fashioned it with a graving tool.” and made it into a molten calf. And they exclaimed, “This is your god,*This is your god Others “These are your gods.” O Israel, who brought you out of the land of Egypt!” (5) When Aaron saw this, he built an altar before it; and Aaron announced: “Tomorrow shall be a festival of יהוה!” (6) Early next day, the people offered up burnt offerings and brought sacrifices of well-being; they sat down to eat and drink, and then rose to dance. (7) יהוה spoke to Moses, “Hurry down, for your people, whom you brought out of the land of Egypt, have acted basely. (8) They have been quick to turn aside from the way that I enjoined upon them. They have made themselves a molten calf and bowed low to it and sacrificed to it, saying: ‘This is your god, O Israel, who brought you out of the land of Egypt!’” (9) יהוה further said to Moses, “I see that this is a stiffnecked people. (10) Now, let Me be, that My anger may blaze forth against them and that I may destroy them, and make of you a great nation.”
DISCUSSION QUESTIONS:
1. Comparing these two texts (the story of Rabbi Akiva and his students and the story of the Golden Calf), what are your takeaways?
2. What do these stories tell us about the seriousness of receiving Torah? How can we today show our respect to the Torah?
3. How do we incorporate respectful joy in our receipt of Torah?
4. What does our tradition tell us about carving out time for sorrow in a period of joy, or joy in a period of mourning?
IN CONCLUSION: how will you observe/celebrate Lag b'Omer today?
Enkindling Community: A Blessing for Lag B’Omer by Devon Spier
A plague raged in Rabbi Akiva’s house
Disrespect was the match
that lit the communal fire.
that extinguished people’s lives.
Leaving only the ashes of misplaced good intentions.
A whole house in ruin.
How do we live after we caused the fire?
How do we repair in the face of looming nothing?
How do we begin after we end?
Let us clean out our lot.
Keep only chesed
Tear down our fences
Keep the wood for a new fire.
The kind that enkindles souls.
That raises good deeds and each one of us toward heaven.
Baruch ata Adonai, ohev amo Yisrael. Amen.
Praise to You, Adonai, who loves Your People Israel and who makes possible our love for each other.

BONUS CONTENT: “Mourning and Meaning Making” by Shira Koch Epstein
My son’s hair is more unruly than usual, though that’s typical for this time of year. In our family, we follow the custom of not cutting our hair during the Omer, the 49 days between Passover and Shavuot. The Omer is treated as a time of mourning — first marking the deaths of many thousands of Jews in the Bar Kochba revolt and subsequent plague in 132 CE, and later taking on significance as the time of year when Ashkenazi Jews frequently experienced pogroms. In a few weeks, we’ll get a reprieve — a picnic, maybe a haircut — on the 33rd day of the count, known as Lag Ba’omer. And we know we will end this period a little more than two weeks after that with the celebration of Shavuot, for not only have we survived massacre and plague, but we have received the Torah and have had harvests of plenty for thousands of years.
And they were following the teaching of Rav Nachman of Breslov, who said that it is forbidden to despair. As long as we carry forward Torah, as long as we reach toward and seek to reflect God’s light, we access a source of hope. As future ancestors, and descendants of Abraham and Sarah, we embody an indomitable spirit that affirms life even in the darkest of times.
What if we could, even now in fresh grief, still weather our despair with the memory of past redemptions? What if our rituals this year could reflect not only the sorrow of those we have lost but also our indomitable spirit, and a stubborn hope for peace and security? What if we allow ourselves this Shavuot to truly receive the gift of Torah to give us strength and hope?
As hair grows and tears flow through this Omer period, we add new stories of collective and personal sorrows. Someday our current sorrows will be memories, woven into the tapestry of our shared destiny, where time and again we “sow in tears and reap in joy,” in the words of the psalmist. As we count down to Shavuot, we are reminded that, just as we stood together at Sinai, we will once again gather in the celebration of Torah and the renewal it promises.