The phenomenon of the rainbow was symbolic of the ability granted to the “light” of ethical and moral conduct to penetrate even the darkest, thickest “cloud cover,” in times when the forces of evil and corruption prevail.
We read toward the end of Parashat Noach of God’s promise to never again flood the earth, as He did in Noach’s time. God proclaims this covenant to Noach and then designates the rainbow as the eternal symbol of His promise: “I have placed My rainbow in the cloud, and it shall be a sign of the covenant between Me and the earth. It shall be, when I place clouds over the earth, the rainbow will be seen in the cloud. And I shall [then] remember My covenant between Me and you…” (9:13-15).
A number of different approaches have been taken to explain the symbolic significance of the rainbow, why it, specifically, was chosen as the symbol of God’s covenant with the earth. One particularly insightful explanation (cited in the Yalkut Yehuda) takes note of the fact that God emphasizes the rainbow’s appearance through a cloud. A careful reading of God’s words in these verses reveals that the rainbow itself does not, independently, serve as the sign of the covenant. Rather, the sign is the rainbow’s appearance within the cloud: “I have placed My rainbow in the cloud, and it shall be a sign of the covenant between Me and the earth…” The sun’s light will penetrate the cloud, and its refraction results in the colorful appearance of the rainbow, thereby announcing God’s promise to all mankind. Until the flood, it seems, the clouds formed too thick a barrier between the sun and the earth to allow for the penetration of any light. The change that God brought about after the flood diminished the strength, so-to-speak, of the clouds, such that they could allow the infiltration of some rays of light, and were unable to produce the kind of rain that fell during the time of the flood.
The phenomenon of the rainbow was symbolic of the ability granted to the “light” of ethical and moral conduct to penetrate even the darkest, thickest “cloud cover,” in times when the forces of evil and corruption prevail. God guaranteed Noach that He will never again allow mankind to degenerate to the point of depravity as they did in that generation, that even the thickest “clouds” would not succeed in obstructing all rays of light. Even when the “clouds” of cruelty, barbarism or decadence cover the sky, when society is overrun by impiety, the “light” of morality will still manage to surface. God gave us His word that even in the world’s darkest periods, it will still be possible to shine the light of faith and sanctity through the dark cloud, and illuminate even the darkest, stormiest skies.