Credit: Takkk, Rainbow in Budapest, CC BY-SA 3.0
Rainbows have a complicated history in Jewish sources. In the Book of Genesis, rainbows are introduced as a sign that the flood that Noah survived was a one-time event.
(יא) וַהֲקִמֹתִ֤י אֶת־בְּרִיתִי֙ אִתְּכֶ֔ם וְלֹֽא־יִכָּרֵ֧ת כָּל־בָּשָׂ֛ר ע֖וֹד מִמֵּ֣י הַמַּבּ֑וּל וְלֹֽא־יִהְיֶ֥ה ע֛וֹד מַבּ֖וּל לְשַׁחֵ֥ת הָאָֽרֶץ׃ (יב) וַיֹּ֣אמֶר אֱלֹהִ֗ים זֹ֤את אֽוֹת־הַבְּרִית֙ אֲשֶׁר־אֲנִ֣י נֹתֵ֗ן בֵּינִי֙ וּבֵ֣ינֵיכֶ֔ם וּבֵ֛ין כָּל־נֶ֥פֶשׁ חַיָּ֖ה אֲשֶׁ֣ר אִתְּכֶ֑ם לְדֹרֹ֖ת עוֹלָֽם׃
(11) I will maintain My covenant with you: never again shall all flesh be cut off by the waters of a flood, and never again shall there be a flood to destroy the earth.” (12) God further said, “This is the sign that I set for the covenant between Me and you, and every living creature with you, for all ages to come.
Of course, rainbows are a natural phenomenon...so what does it mean to say that it is also a supernatural sign? Nachmanides, the great 12th century Torah commentator, explains that both can be true. Rainbows are a scientific phenomena, loaded with extra significance for those who hold the memory of Noah and the flood.
זאת אות הברית אשר אני נותן המשמע מן האות הזה שלא היה קשת בענן ממעשה בראשית ועתה ברא ה' חדשה לעשות קשת בשמים ביום ענן ואמרו בטעם האות הזה כי הקשת לא עשאו שיהיו רגליו למעלה שיראה כאלו מן השמים מורים בו ...אבל עשאו בהפך מזה להראות שלא יורו בו מן השמים וכן דרך הנלחמים להפוך אותו בידם ככה כאשר יקראו לשלום למי שכנגדם.. ואנחנו על כרחנו נאמין לדברי היונים שמלהט השמש באויר הלח יהיה הקשת בתולדה...וכאשר נסתכל עוד בלשון הכתוב נבין כן כי אמר את קשתי "נתתי" בענן ולא אמר "אני נותן" בענן כאשר אמר זאת אות הברית אשר "אני נותן" ומלת קשתי מורה שהיתה לו הקשת תחלה ולכן נפרש הכתוב הקשת אשר נתתי בענן מיום הבריאה תהיה מן היום הזה והלאה לאות ברית ביני וביניכם שכל זמן שאראנה אזכיר כי ברית שלום ביני וביניכם...
"This is the sign of the covenant that I am giving": it seems from this "sign", that the rainbow was not in the cloud from creation and now God did a new act of creation to make the rainbow in the sky on a cloudy day. And the reason for the sign was explained - that the rainbow was not created so...to look as though someone is shooting arrows from heaven, but rather the opposite, to show that no one is shooting from heaven. This is the way of warriors, to turn their bow over in their hands to indicate that they are calling for peace to those who are fighting against them....We are forced to believe the words of the Greeks, that from the shining of the sun in moist air the rainbow will come to be as a result... And when we look again at the language of the text we will understand this, because it says "I have put my rainbow in the cloud", and it didn't say "I am putting in the cloud" when it said "this is the sign of the covenant that I am putting". And the word "my rainbow" shows that God already had a rainbow from the beginning. Therefore, we should explain the passage thus: The rainbow which I put in the cloud from the day of creation, should be from this point onwards a sign of the covenant between Me and you.
In other words, rainbows occur when light shines through water, but they were chosen as a sign for this covenant because they look like an overturned bow. This sign of surrender will henceforth indicate that God remembers the promise and will no longer destroy the world.
Because of this association, Rabbinic sources in several places indicate that even the most colorful rainbow may be a bad sign. If God is reminding us that there's a pact in place about not destroying the world, then maybe that means that were it not for that promise, we would be in be big trouble.
If we run with that reading of the rainbow, then NOT seeing a rainbow is actually a really great sign, as indicated below:
...רבי חזקיה בשם רבי ירמיה כל ימיו של רבי שמעון בן יוחאי לא נראתה הקשת בענן...
Rabbi Chizkiyah said in the name of Rabbi Yirmiyah: During the lifetime of Rabbi Shimon bar Yochai, a rainbow was never seen in the clouds.
Rabbi Shimon bar Yochai is one of the central figures of Lag B'Omer (search for his name on Sefaria to find out more!). Tradition has it that he died on Lag B'Omer. Rashb"i, as he is affectionately known, was a complicated character, but here the Talmud attests to his greatness: Throughout his lifetime, rainbows never appeared. The source below both explains this cryptic statement, and relates it to Lag B'Omer.
מנהג ישראל אשר התלמידים בני בי רב יורו בקשת ביום הזה והנה שמעתי מאת כבוד אדומ"ו ברב הקדוש מהרמ"מ זצוק"ל הטעם הוא כי בימי ר' שמעון לא נראתה הקשת. והנה ביום עלותו למרום עושין הסימן בזה עכ"ד. והוא כעין ללמד בני יהודא קשת. ונ"ל ע"ד דברי אדמ"ו דהנה אמר רשב"י לר"א ברי' (בזהר) ברי לא יתצפי לרגלי דמשיחא עד דתתחזי קשתא בגוונין נהורין. הוא סימן התגלות אור של מלך המשיח. אשר יגלה האור בי טוב הגנוז. הנה ביום הזה אשר נכתב הס' הקדוש הזהר שהוא מהארת האור כי טוב הגנוז. מפי ביצינא קדישא. וזה מאיר לנו בגלות עד יתגלה בזכות זה משיח צדקינו יהי אור זה אור"ו של מלך המשיח והסי' מסור בידינו בשעתא דתתחזי קשתא בגוונין נהורין. ע"כ ביום זה לסימן הטוב הלזה ויורו המורים בקשת:
One particular custom practiced on the day of Lag B'Omer is unique: Children go to parks and fields to play with bows and arrows. What is the reason for this peculiar custom? One well-known explanation has to do with the fact that during Rabbi Shimon's lifetime, no rainbow ever appeared in the sky. This is profoundly significant, because Genesis relates that the rainbow represented God's covenant never to destroy the world again even if the human race would degenerate to its status prior to the Flood. But as long as Rabbi Shimon was alive, his merit and piety alone were enough to ensure that God would not regret His creation, with no need for the rainbow. On the day of Rabbi Shimon's passing, however, the world was in need of the rainbow. Thus, each year on that day we recall this man's greatness by playing with the bow.
This 19th century Chasidic text brings it all together: Rabbi Shimon bar Yochai was such a wonderful person that his very presence kept the world from ever being judged so negatively that God would feel tempted to bring destruction to the world. When he was no longer a part of the world, we once again needed a rainbow to remind God not to destroy humanity. And so, in memory of Rabbi Shimon bar Yochai, on Lag B'Omer everyone steps up and plays with bows and arrow, to echo the protection of the rainbow.
To Discuss:
1) What associations do you have with rainbows?
2) When you think of someone whose presence has or had an impact on the entire world, who do you imagine?
3) With the exception of some archery classes, most of us probably don't use bows and arrows regularly, even on Lag B'Omer. What other symbolism might we incorporate into the holiday in light of these rabbinic ideas?