When Was the Rainbow Created? The Bible Meets Science

Translation of the biblical text is from RJPS. Unless otherwise noted, translations of rabbinic and medieval texts are by the author and the editors.  I would like to thank the editors of TheTorah.com for all the work they put into this piece. I would also like to thank my colleague Prof. Eric Lawee, Bar-Ilan University, for his helpful comments on an earlier draft.

Aristotle, Meteorologica 3.4 (373a–b), in Jonathan Barnes, ed., The Complete Works of Aristotle: The Revised Oxford Translation, Bollingen Series 71.2 (Princeton University Press, 1984), 1.602, with slight modifications.

How accurate or scientific Aristotle's explanation is compared to modern scientific ones is beside the point. For medieval commentators, this was a scientific fact that made the biblical claim problematic. The main Arabic transmitter of Aristotle’s views on meteorology was Yaḥya ibn al-Biṭrīq (d. 806), who translated a compendium compiled from a number of works, via a Syriac intermediary. This is what Samuel Ibn Tibbon used for his Hebrew version, Otot ha-Shamayim [The Signs of the Heavens]. See Teresa Bernheimer, “Retracing the Reception of Greek Ideas on the Rainbow: Transformations in Pre-Modern Hebrew and Arabic Sources,” Jewish Culture and History 26.4 (2025): 476–487 [p. 481].

Saadia’s Judeo-Arabic Tafsir biblical translation of Gen 9:13. See Joseph Derenbourg, ed. and trans., Version Arabe du Pentateuque de R. Saadia ben Iosef al-Fayyoumi (E. Leroux, 1893; repr. Olms, 1979), 16.

R. Obadiah Sforno (1475–1550) agrees with Saadia:

^{ספורנו, בראשית ט:יג} אֶת קַשְׁתִּי נָתַתִּי בֶּעָנָן – סִדַּרְתִּי שֶׁיִּהְיֶה בַּטֶּבַע.

^{Sforno, Gen 9:13} “I have set my bow in the cloud” — I arranged that it should be [so] in nature.

The list continues:

^{משנה אבות ה:ו} ...וְהַמָּן, וְהַמַּטֶּה, וְהַשָּׁמִיר, וְהַכְּתָב, וְהַמִּכְתָּב, וְהַלּוּחוֹת.

^{m. Avot 5:6} …the manna, the staff [of Moses], the shamir (according to Jewish lore, a worm that could cut stone, which King Solomon used to build the Temple), the letters, the writing, and the tablets. 

Ibn Ezra wrote two commentaries on Genesis. The first (standard) commentary, written in Lucca, Italy, is more terse, focusing on peshat. The second, written later in Rouen, France, is more expansive, but was left unfinished. This is from Ibn Ezra’s first commentary, in Menachem Cohen, ed., מקראות גדולות הכתר: בראשית [Mikraʾot Gedolot ‘Haketer’: Genesis], part 1 (Bar-Ilan University Press, 1997), 102–103. Both commentaries are also accessible at alhatorah.org.

R. Moses ben Judah min Hane’arim, in his supercommentary, identifies Ibn’s Ezra’s source as Aristotle’s Meteorologica (Otot ‘elyonot). See Moses ben Judah min Hane‘arim, Be’ur ‘al be’ur ha-Torah me-et Avraham ibn ‘Ezra, ed. Ofer Elior (Ben-Gurion University of the Negev Press, 2015), 36.

This view somewhat resembles those of R. Nissim Gerondi and Abarbanel; see below.

Judah Leon ben Moses Moskoni (14th century, Ohrid/Majorca), in his supercommentary on Ibn Ezra, Even Ha‘ezer, expands on this:

וכאשר עבר זמן המבול ונתחזק כח השמש להאיר ולהעלות ולהתיך, נראתה הקשת. ושמה האל ית׳ ברית עולם לנח ולבאים אחריו, כי כל הימים אשר תראה הקשת בענן לא נפסד מהמבול. כי הקשת היה ברית כרותה לנו על זה.

When the time of the flood passed and the sun’s power to shine, to raise [vapor] and to dissolve was strengthened, the rainbow appeared. God, may He be exalted, made it an everlasting covenant with Noah and those who came after him, that all the days the rainbow is seen in the cloud we would not be destroyed by a flood, for the rainbow was a covenant made with us about this.

Judah Leon b. Moses Moskoni, אבן העזר על פירוש התורה לר׳ אברהם אבן עזרא: בראשית [Eben Ha-ʿEzer: Supercommentary on Ibn Ezra’s Torah Commentary, Genesis], ed. Howard Kreisel, Goldstein-Goren Library of Jewish Thought 28 (Ben-Gurion University of the Negev Press, 2021), 103.

Ibn Ezra, second commentary, in Cohen, Mikraʾot Gedolot ‘Haketer’: Genesis, 102.

As to why the rainbow functions as a sign, Ibn Ezra responds:

^{אבן עזרא, פירוש שני, בראשית ט:יד} ואם ישאל שואל: למה האות בקשת, בעבור כי היא אות לעולם שיכלא הגשם.

^{Ibn Ezra, second commentary, Gen 9:14} And if someone asks why the sign is in the rainbow — because it is an eternal sign that the rain will be restrained.

The Hebrew of Ramban’s commentary is from Charles B. Chavel, ed., פירושי התורה לרבינו משה בן נחמן [Commentary on the Torah by R. Moshe Ben Nachman], vol. 1 (Mossad Harav Kook, 1959). Translations are from Ramban (Nachmanides), Commentary on the Torah: Genesis, translated and annotated by Charles B. Chavel (Shilo, 1971), accessible at Sefaria.org.

Nachmanides then argues, like Saadia, that the biblical phrase קשתי נתתי supports this:

^{רמב"ן, בראשית ט:יב} 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 תורה שה[י]תה לו הקשת תחלה.

^{Ramban, Gen 9:12} And when we examine more closely the language of Scripture we will understand that this is so, for He said, “I have set My bow in the cloud.” He did not say, “I am setting in the cloud,” even as He said, “This is the sign of the covenant which I am making.” Moreover, the word kashti (my bow) — [in the possessive form] — indicates that He possessed the bow previously.

He states:

^{רמב"ן, בראשית ט:יב} ולכך נפרש הכתוב: הקשת אשר נתתי בענן מיום הבראה, תהיה מן היום הזה והלאה לאות ברית ביני וביניכם, שכל זמן שאראנה אזכור כי ברית שלום ביני וביניכם.

^{Ramban, Gen 9:12} Therefore, we shall explain the verse thus: “The rainbow which I have set in the clouds from the day of creation will be from this day on a sign of the covenant between Me and you; whenever I will see it, I will remember that there is a covenant of peace between Me and you.”

The Hebrew text is from Nissim b. Reuben Gerondi, פירוש על התורה [Commentary on the Torah], ed. Leon A. Feldman (Makhon Shalem, 1968), 124–129 (on Gen 9:12–17). Bracketed words in the Hebrew are Feldman’s supplements. Translations of the commentary are by the editors.

In his sermons, Nissim offers a different explanation, claiming that the rainbow would not have been visible at all before the flood because the lower elements of water and earth dominated the higher elements of fire and air. After the flood, God strengthened the element of fire so that it was not overpowered by the lower elements, which allowed the rainbow to be visible. See Nissim b. Reuben Gerondi, דרשות הר"ן [Derashot ha-Ran], ed. Leon A. Feldman (Makhon Shalem, 1973; 2nd ed. 2003), derashah 1; English in Derashos HaRan: Discourses of the Ran, trans. Yehuda Meir Keilson, 2 vols. (Mesorah, 2019), 1:42–44.

He explains that most of the special things that the sages say were created on the eve of Shabbat were, like the rainbow, not actually created at that point, but created in potentia, meant for a later time:

^{אברבנאל, בראשית ט:יג} ואל תקשה על זה מאמרם ז"ל שהקשת נברא בין השמשות כי זהו עצמו יורה על מה שפירשתי. לפי שכל הדברים שאמרו שנעשו בין השמשות לא נעשו אז בפעל אבל היו עתידין להעשות בזמניהם כמו אילו של יצחק והבאר ופי הארץ ופי האתון ושאר הדברים שזכרו שאין ספק שלא היו בפועל מתחלת הבריאה אלא ששם הקב"ה אז כח בנמצאים שיולידום וימציאום למציאות כל א׳ בזמנו וכן היה הקשת כי לא היה בפועל בענן כי אם אחר הברית ועל זה נאמר "את קשתי נתתי בענן והיתה לאות ברית וגו׳" להודיעו שידקדק את העננים כ"כ שתתרשם בהם תמונת השמש באמצעות נצוציה.

^{Abarbanel, Gen 9:13} Furthermore, do not be troubled by the saying of the sages that the rainbow was created at the twilight [of Shabbat] because this itself points to what I have explained, because all of the things that they said were created at twilight were not actually created but were intended to appear at their proper times, like Isaac’s ram, the well [of Miriam], the mouth of the earth [that swallowed Korah and his followers], the mouth of the donkey [that spoke to Balaam] and other things they enumerated, which undoubtedly did not actually exist from the beginning of creation, but rather God placed the power in the existing things so that they would give rise to them and bring them into reality each one at its [proper] time. So it was with the rainbow, because it did not actually exist in the cloud until after the covenant, and about this it is said “I have set my bow in the cloud and it will be a sign of the covenant between me and the earth” (Gen 9:13), to tell him to thin out the clouds to such an extent, so that the image of the sun would appear in them through its rays.

Isaac Abarbanel, פירוש על התורה [Commentary on the Torah], vol. 1: Bereshit (Benei Arbel, 1964), 164–165; also at alhatorah.org. Author’s translation.

He explains:

^{אברבנאל, בראשית ט:יג} ... ולרבוי העבים ועביים היו העננים המתילדים מהם כל כך עבות וגסות שלא היו יכולין נצוצי השמש לעבור בהם עד שלא היה מתרשם מראה הקשת לא באויר ולא בענן ולכן לא היה חום השמש ונצוציו יכולין לשלוט עליהם ולדקדקם ולהתיך קצת לחותם והיו מפני זה מעותדים להביא מבול לעולם

^{Abarbanel, Gen 9:13} … because of the multitude of the heavy clouds (ʿavim) and their thickness, the clouds that they gave rise to were so thick and gross that they prevented the sun’s rays from passing through them, which meant that the appearance of the rainbow was prevented both in the air and the cloud, and therefore the heat of the sun and its rays had no control over them and were not able to thin them out and dissipate their moisture, and this enabled them to bring a flood upon the earth.

This section was added by the editors.

Solomon Dubno, Bi’ur on Gen 9:13, in Moses Mendelssohn, ספר נתיבות השלום [Sefer Netivot ha-shalom] (Berlin, 1783), vol. 1; also at alhatorah.org. This comment closely follows that of Nachmanides (see above). He considers some of the explanations offered by earlier exegetes:

^{ביאור, בראשית ט:יג} והנה הראב"ע כתב כמתנבא שה׳ חיזק אור השמש אחר המבול, מה שלא היה קודם זה, ולכן לא היה כח בלהט ההוא להראות הקשת.

Now Ibn Ezra wrote, as if prophesying, that God strengthened the sun’s light after the flood, which had not been the case before, and therefore that heat did not [previously] have the power to show the rainbow.

והיותר נעים ומקובל בכל הפירושים לדעתי הוא פירוש הרמב"ן בזה...

The most pleasing and acceptable of all the interpretations, in my opinion, is the Ramban’s [Nachmanides] on this...

See above, nn. 13 and 14. This view remained popular among some like-minded modern commentators, such as Isaac Samuel Reggio, ספר תורת האלהים [Sefer Torat ha-Elohim] (Vienna, 1821), and Moses Isaac Ashkenazi Tedeschi (Hoʾil Mosheh, on Gen 9:13).

He explains:

^{ר׳ נ"ה וויזל, אמרי שפר, בראשית ט:יג} את קַשְׁתִּי נתתי בענן והיתה לאות ברית ביני ובין הארץ – דע כי הַקֶשֶׁת בענן מוֹצָאָהּ מן השמש העומד מנכח לה. כי אורה ירשום התמונה הזאת לנגד עינינו בענן, כשתזרח בטפי המים הנתלים בענן, ומשם יגיעו לאישון בת עינינו, ונראה עגול חצי השמש שממעל לארץ כדמות קֶשֶׁת.

^{Wessely, Imrei Shefer, Gen 9:13} “I have set my bow in the cloud, and it shall be a sign of a covenant between me and the earth” — Know that the rainbow in the cloud has its origin in the sun standing opposite it, for its [the sun’s] light traces this image before our eyes in the cloud when it shines on the drops of water suspended in the cloud, and from there they reach the pupils of our eye, and we see the half-circle of the sun that is above the earth in the form of a bow.

Text from Naphtali Herz Wessely, אמרי שפר [Imrei Shefer, Lovely Fawns; see Gen 49:21], (Mekize nirdamim, 1868-1871), commentary on Gen 9:13; also at alhatorah.org. Translation by the editors.

Samuel David Luzzatto, פירוש שד"ל על חמשה חומשי תורה [Shadal’s Commentary on the Pentateuch], ed. Pinchas Schlesinger (Dvir, 1965), 50, on Gen 9:13; also at alhatorah.org. Translation by the editors.