When I was a child, few things filled me with as much joy and wonder at God’s creation as the rainbow. For a short while I even believed the legend of the pot of gold waiting at its end—until my father, ever the scientist, explained the optics. A rainbow is light bent through drops of water, and it depends on where you stand: however far you walk toward the place where it seems to touch the ground, that place moves away with you. No one has ever reached it.

I still love that God chose this sight as the sign of His covenant after the flood: “I have set My bow in the cloud, and it shall be a sign of the covenant between Me and the earth” (Bereishit 9:13). The rainbow seems to reach down to the land, and the covenant it signals reaches the land as well.

But why should the earth be a party to a covenant at all? Because in the opening chapters of Bereishit, the earth keeps paying for human failures. After the first sin, God tells Adam, “Cursed is the ground because of you” (Bereishit 3:17). Cain is “cursed from the ground” that received his brother’s blood (Bereishit 4:11). When Noach is born, his father names him with a hope: “This one will comfort us from our work and the toil of our hands, from the ground that God has cursed” (Bereishit 5:29). And when humanity turns violent, it is the earth that is said to be corrupted: “The earth was corrupt before God, and the earth was filled with violence… for all flesh had corrupted its way upon the earth” (Bereishit 6:11–12). Adam, the Man, was taken from the adamah, and the adamah shares its fate.

After the flood, God makes a promise that seems to answer all of this: “I will not again curse the ground because of humanity, for the inclination of the human heart is evil from its youth; nor will I again strike down every living thing, as I have done” (Bereishit 8:21).

The word for “because,” “ba’avur,” is the same word God used in Eden. The curse that began “because of you” ends “because of humanity.” But what reason does the verse give? In his commentary to the Book of Genesis, Rabbi Umberto Cassuto notes two possible readings. In the first reading, the clause about the evil inclination explains God’s mercy: since humans are flawed from youth, they deserve forgiveness. Cassuto rejects this, and his reason is simple. Human nature was described in exactly these terms before the flood—”every inclination of the thoughts of his heart was only evil all day” (Bereishit 6:5)—and that nature was precisely what brought the flood. It cannot suddenly become grounds for God’s mercy. The clause instead explains the curse itself: God will no longer curse the earth on account of human evil. The ground that paid for Adam, for Cain, and for the generation of the flood, is released from paying for us.

In other words, nothing about humanity has changed. Cassuto observes that only the tone has softened: “every inclination” becomes “the inclination,” “only evil” becomes “evil,” “all day” becomes “from its youth.” Before the flood, human evil was described in full because it justified the punishment; afterward, it is mentioned only in passing, inside a decision of mercy. What has changed is not us, but God’s stance toward us.

This is where the rainbow comes in. God says, “When the bow is in the cloud, I will see it and remember the everlasting covenant” (Bereishit 9:16). The sign is addressed first of all to God. It appears in rain clouds, at the very moment when the verdict of 6:5 could apply again, and it recalls a promise made with full knowledge of who we are. A rainbow is therefore beautiful and humbling at once: it tells us that we are still the humanity of 8:21, and that we are being spared anyway.

Perhaps this is why Jewish tradition surrounds it with such care. When we see a rainbow, we bless God “who remembers the covenant” (Berakhot 59a), echoing the very words of the Torah. Yet the Talmud warns against staring at a rainbow (Chagigah 16a). We are meant to notice it, to bless, and to lower our eyes. Staring at the rainbow might comfort us, but the Rabbis chose otherwise. After all, the sign is God’s to look at, not ours—and a mercy we could gaze at freely might too easily become a mercy we take for granted.

That danger is real. A promise that depends on no one’s merit raises a hard question: if God’s mercy does not wait for us to improve, why try? I think the answer runs the other way. A covenant that depended on our goodness would collapse at our first failure—that was the world of 6:5, and it ended in a flood. Because the promise holds no matter what, we can strive to be better without fearing that every fall is final. Mercy is not permission to stay as we are; it is the ground that makes trying possible.

Yet the Torah does not leave us with a promise alone. In a world God regretted making, God had seen Noach, a man with the same human heart, but a man in whom there was still hope (Bereishit 6:8). And Noach justifies that hope: his first act when he steps out of the ark is to build an altar, and “God smelled the pleasing aroma,” re’ach ha-nicho’ach—a play on Noach’s own name (Bereishit 8:20–21). Human nature has not changed, and the offering is not a merit that outweighs it. The offering is a turning toward God, and mercy answers it. The Talmud teaches that in the lifetime of Rabbi Yehoshua ben Levi no rainbow was ever seen, because a generation with such a righteous person did not need one (Ketubot 77b). Each of us can be that person—not by becoming flawless, but, like Noach at the altar, by turning toward God.

My father was indeed right: there is no pot of gold, and no one ever reaches the place where the rainbow touches the ground. Yet that place—where heaven seems to meet the earth—is exactly what we are asked to aim for. Every time we turn toward God, as Noach did at the altar, we bring heaven a little closer to the ground. And until the day we no longer need the sign, the rainbow keeps appearing, a reminder that God’s mercy walks with us at every step.