Rabbi Pinḥas said in the name of Rabbi Hoshaya: Equivalent to the space between the earth and the firmament, so is the distance between the firmament and the upper waters. “Let there be a firmament in the midst of the water” – at the midpoint between them. Rabbi Tanḥuma said: I will say the source. Had it been stated: “God made the firmament and he divided between the waters that were on the firmament,” I would have said that the upper waters rest directly upon the firmament.
But since it says: “And the waters that were above the firmament” (Genesis 1:7) – [it indicates that] the upper waters are suspended [above the firmament] by the word of God. Rabbi Aḥa said: It is like the flame in a lamp.5The wick does not stand on the bottom of the lamp, but is suspended above it, as it were, by the oil. And its fruits are rainwater.6The upper waters produce rain, but, as when a tree produces fruit, they are not depleted by the rainfall.