“God said: Let there be a firmament in the midst of the water, and let it divide between water and water” (Genesis 1:6). “God said: Let there be a firmament” – it is written: “He roofs His upper chambers with water” (Psalms 104:3). The way of the world is that a flesh-and-blood king builds a palace and roofs it with stones, wood, and earth. But the Holy One blessed be He is not so, He roofed His world only with water, as it is stated: “He roofs His upper chambers with water.”