Jewish Philosophy

Eyes and Vision in the Torah: The Colours of the Rainbow
Date Uploaded: 
Monday 4th August 2014

by Menachem Salasnik, Israel Educator

After the flood, G-d made a covenant, promising that He would never again destroy the whole world with a deluge. As a sign, He showed Noach a rainbow (Bereishit 9:13).
When we see a rainbow, we make a blessing with specific reference to that event – ‘Blessed are You … Who remembers the covenant, is trustworthy in His covenant and fulfils His word’ (Zocher HaB’rit V’Ne’eman Bivrito V’Kayam B’Ma’amaro).

A rainbow is supposed to invoke mixed emotions. On the one hand, it is beautiful and aweinspiring. The prophet Yechezkel (Ezekiel 1:28) in his vision of G-d’s Angelic Entourage described the brilliant light that he saw surrounding G-d’s Presence as looking similar to a rainbow. (Due to this comparison, out of respect, we do not stare at a rainbow longer than the time it takes to say the blessing.)

Yet there is a darker side to a rainbow. If a rainbow indicates that G-d will not destroy the world, its appearance implies that were it not for that promise, the world has reached a state where it would be appropriate for it to be destroyed. In line with this idea, the Talmud relates several people who were so great that in their lifetime a rainbow was never seen, as their merit alone kept the world intact.

Of all the possible signs, why did G-d choose a rainbow?

Rainbows occur when the sun is shining and there is rain or water in the air. When light travels from one medium to another (e.g. from air to water) it changes speed and this causes the light to bend (known as refraction). Different wavelengths of visible light appear as different colours, ranging from longer wavelength red to shorter wavelength violet. The amount that light is refracted depends on its wavelength – shorter wavelengths slow down and bend more than longer wavelengths. White light is a combination of all the wavelengths of visible light. When that light is refracted, the varying bend of the different wavelengths causes the light to split into its component colours. (The eye focuses light using refraction; there is therefore a slight colour-split. This is why optometrists use the red/green test to ensure that the range of colours are sitting appropriately on the retina.)

Rabbi Shimshon Raphael Hirsch (d. 1888) explains that G-d sends His holy and unadulterated spiritual light to the world. But there is a large range of people; some who will stay close to that original light, like the red colour, while others will distort and bend it far away towards darkness, like the violet. G-d’s postflood promise was that even though His light and His word are being distorted and the world is moving off-track from the spirituality it was designed for, He will nevertheless not destroy it. Rather He will allow His light to continue to shine, in the hope that all humanity will eventually make the journey back to the original path.

We may not always be able to influence the whole world but we can try to change ourselves. When we next see a rainbow, perhaps we can think about a small change we can make to help the world get closer to the original light.

Menachem Salasnik is a Geriatric and Low Vision Optometrist