The Rainbow and its warnings?
The rainbow is commonly thought of as positive sign among Jews. The sign given after the mabul that Hashem will never again destroy the whole world, and the Bavli [Chagiga 14b] that relates that :-
"... when Reb Yehoshua and Rebbe Yose HaKohen heard about how wondrous it had been when Reb Elazar ben Arach was doresh the Maaseh Merkavah (see whole story there) they had been traveling and they stopped to speak about the Maaseh Merkava as well. Although it was in the summer, the sky filled with clouds and a rainbow appeared, all the angels gathered to listen to them just as people gather around to watch ‘shtik’ being performed in front of a chassan and kallah..."
The Zohar relates that the colors of the rainbow correspond to Chesed, Din and the balance between them.
However there is a negative side it seems as well:-
"...Elijah of blessed memory and R. Joshua b. Levi were sitting and studying together, when they came to a ruling of R. Simeon b. Yohai. Said one: ' Here is the author of the ruling: let us go and question him about it.’ So Elijah of blessed memory went to him, ' Who is with you? ' he asked. ' The greatest of his generation, R. Joshua b. Levi,’ he answered. ' Has the rainbow appeared in his days?’ if so he is not fit to talk to me..." [Bereshith Rabbah 35:2]
also Mishnah Berura quotes lehalacha that even a though a blessing is to be made on a rainbow, one should not inform others about a rainbow since it is a bad sign. The rainbow signifies that if not for the covenant the world would be eligible for destruction.
Why?
If you apply a little modern science to the rainbow you now 'know' that a rainbow is the result of refracted sunlight passing through raindrops to reveal its glorious constituent spectrum emblazened across, the sky. So the dazzling colours are the product of the 'separation' of light into its embedded pluralities and separateness.
Ask yourself a question, which way do you look when a Rainbow is in the Sky toward it or toward the source of the light?
It seems to me that the rainbow can serve as a very good metaphor for our relationship with Hashem. We cannot look at the Sun it blinds us, but once the light has been refracted we are content to stare and wonder at the multiple colors and ignore the source of those colors.
The multiplicitous Tzimtzum our 'Chessed Bubble' of existence refracts the Ohr to give us a 'Rainbow' existence of multiplicity, and color, occupying us with such a wonder that we turn our backs on the source of that wonder.
The warnings are clear when thinking of the rainbow, don't be dazzled by multiplicity keep in mind the true origin of that wonder. Although you cannot look at the source without suffering blindness turn your heart to the source and don't encourage others to get caught in the spectacular projection of the world, keep in mind Hashem, the true source of all and the only truth. The colors are embedded in HIm but when separated they have no meaning other than a glorious spectacle.
