What Noah’s Rainbow Really Means

God destroys the entire world, spares one family, and then makes a promise never to do it again. What sign does he choose for this covenant? A rainbow. Not a mountain that stands forever. Not a star that shines in the heavens. Not even a monument of stone that Noah might build. A rainbow—a fleeting phenomenon that appears only under specific atmospheric conditions and vanishes within minutes.

This choice seems almost careless until you look closer at what the rainbow actually represents.

The text is clear enough: the rainbow marks God’s promise never again to destroy humanity with flood waters. But the text doesn’t explain why He chose this sign. Why does the Creator of the universe select a temporary, weather-dependent display of refracted light to memorialize the most significant covenant in human history?

The answer lies hidden in the spectrum itself.

Rabbi Pinchas Polonsky offers a striking interpretation that unlocks the rainbow’s deeper meaning. The rainbow stretches across the entire color spectrum from red to violet, and this range is not arbitrary. In Hebrew, adom, meaning “red,” connects linguistically to adamah, meaning “earth.” Red represents the lower levels of existence, the material, the physical ground beneath our feet. At the opposite end of the spectrum lies techelet, the indigo-violet hue that is similar to the word tachlit, meaning “goal” or “purpose”—that which draws us upward toward something higher.

The word techelet itself appears in the commandment regarding the ritual fringes:

The blue thread serves as a visual reminder of our highest aspirations, our connection to the Divine. It is the color of the heavens, representing spiritual elevation and the ultimate goal that leads a person toward the Almighty.

When God placed the rainbow in the sky, He was making a declaration about the new reality of human existence. The spectrum from adom to techelet—from earth to heaven, from base materiality to spiritual striving—represents the full range of human possibility. After the Flood, God essentially announced: “I have reconciled Myself to man’s imperfections. I have removed his special powers; now let him be multi-faceted. There are the evildoers and there are the righteous. For the sake of the righteous I will not destroy the evildoers. Humanity is now a multi-faceted, polychromatic community.”

But if the rainbow symbolizes this new multi-faceted reality, what does that tell us about the world before the Flood?

The world before the Flood was, in a sense, black and white. Evil was so overwhelming that every person fell into one of two categories: complete villain or righteous individual. There was no middle ground, no gradation, no spectrum. The monochrome world produced monochrome people.

After the Flood, everything changed. The world transformed from black and white into full color. Ambiguity entered human experience in ways previously unknown. People no longer fit neatly into two categories. The righteous struggled with imperfection; the wicked retained glimmers of goodness. Humanity became layered, complex, contradictory—exactly like the rainbow that now arched across the sky.

The rainbow, then, is not merely a promise that God will not destroy the earth again. It represents something far more radical: divine acceptance of human moral complexity. God looked at the new world and declared that He would sustain it precisely because of its diversity, its mixture of good and evil, its refusal to be reduced to simple categories.

Here’s the critical insight: the reason God promises never to flood the earth again is directly tied to humanity’s transformation. Before the Flood, God said man’s heart was “evil all the time” (Genesis 6:5), and this justified total destruction. After the Flood, God says essentially the same thing—”the devisings of man’s mind are evil from his youth” (Genesis 8:21)—but now draws the opposite conclusion: therefore, I will never destroy the world again. How can the same premise—human evil—lead to two contradictory conclusions?

The answer lies in what changed about humanity itself. The pre-Flood world operated in absolutes. People were either completely righteous or utterly corrupt. Noah lived in a black-and-white world where the categories were binary. Evil was so overwhelming, so total, that it infected everything. When humanity turned wicked, there were no gradations, no mixed cases, no complexity to prevent the slide into absolute corruption. The entire generation became purely evil, and the world had to be destroyed.

After the Flood, humanity became polychromatic. People no longer fit into neat categories. The righteous struggle with imperfection. The wicked retain glimmers of conscience. Every person contains both adom and techelet, both earthbound materiality and heaven-reaching aspiration. People became layered, contradictory and impossible to reduce to a single moral category.

This transformation is what prevents another flood. When humanity is monochrome—when people can be purely evil without any mitigating complexity—total corruption becomes possible and total destruction becomes necessary. But when humanity is polychromatic, when every person contains multiple colors along the spectrum, absolute evil cannot take hold. The righteous exist alongside the wicked, and their coexistence creates a stability that the pre-Flood world lacked. Rabbi Polonsky explains that God essentially declared: “I have reconciled with man’s imperfections. I have removed his special powers; now let him be multi-faceted. There are the evildoers and there are the righteous. For the sake of the righteous, I will not destroy the evildoers. Humanity is now a multi-faceted, polychromatic community.”

The rainbow is God’s signature on this new arrangement. Its spectrum from red to violet mirrors the spectrum of humanity from material to spiritual, from wicked to righteous. God is declaring that He has made peace with a world where the wicked persist because the righteous persist, and where the world endures not despite this mixture but because of it.

Rabbi Polonsky offers a warning embedded in this teaching: we should not complain that life has become too complicated. We should not wish for a simpler world where everything is morally clear-cut, where people are either purely good or purely evil. That desire for simplicity, for a world of absolutes, leads directly to catastrophe. The Flood was the cost of a black-and-white world. Complexity is the price we pay for survival.

But there’s something else here, something more hopeful. When humanity was monochrome, change was nearly impossible. If you were purely evil, you were locked into that category. Even if you were purely righteous, you stood no chance of moving an entire generation toward goodness. The pre-Flood world was static in its extremes. But a polychromatic world is dynamic. When every person contains both adom and techelet, both the earthly and the heavenly, there is always room for movement along the spectrum. The wicked person who retains a glimmer of conscience can be reached. The righteous person who struggles with imperfection can grow. No one is irredeemable; everyone can improve.

This is what the rainbow actually promises: not just that God won’t destroy us, but that He believes in our capacity to move toward the violet end of the spectrum even while we remain rooted in the red. The covenant is God’s declaration that a world of moral complexity is a world of moral possibility. The mixture itself—the fact that good and evil coexist within every person—means that change is always possible, that growth is never foreclosed, that no individual or generation is beyond hope.

When you see a rainbow, you are looking at more than a promise about water. You are seeing God’s commitment to a world where transformation is possible precisely because perfection is impossible. You are witnessing divine faith in humanity’s capacity to move along the spectrum, to reach upward toward techelet even while standing on adom. The covenant of the rainbow is not a promise of perfection. It is a divine commitment to a world where the mixture of good and evil creates both the stability to endure and the possibility to grow. This is a sustainable imperfection with an upward trajectory—and that is exactly what God intended.

To learn more of Rabbi Pinchas Polonsky’s insights on the Bible, order The Universal Torah: Growth & Struggle in the Five Books of Moses – Genesis Part 1 today!