“God called the firmament heavens. It was evening and it was morning, a second day” (Genesis 1:8). “God called the firmament heavens [shamayim]” – Rav said: [The word indicates] fire [esh] and water [mayim]. Rabbi Abba bar Kahana said in the name of Rav: The Holy One blessed be He took fire and water and integrated them with one another, and from them the heavens were made.
Alternatively, shamim is written,22The letters of shamayim can also be read shamim. as they assess [shamim] the actions of the people. If they merit, “the heavens declare his righteousness” (Psalms 97:6); if not, “the heavens reveal his iniquity” (Job 20:27). Another matter, shamayim – because the creations wonder [mishtomem] in their regard, saying: ‘Of what do they consist? Are they of fire, are they of water?
It is a wonder.’ Rabbi Pinḥas said in the name of Rabbi Levi: He [God] came and settled it: “He roofs His upper chambers with water” (Psalms 104:3); that is, they are of water. [Another interpretation: The word indicates] dyes [samim] – just as with dyes, some are green, some are red, some are black, and some are white, so, too, the heavens, at times they are green, at times they are red, at times they are black, and at times they are white.
Rabbi Yitzḥak said: “Shamayim” – sa mayim, bearing water.23The upper waters are on top of the heavens. It is analogous to milk that was placed in a bowl. Until a drop of rennet falls into it, it is loose. When one drop of rennet falls into it, it congeals and becomes set [omed].
So, too, “The pillars [amudei] of heaven were loose” (Job 26:11) – the heavens became set when He put His rennet in them, “and it was evening and it was morning, a second day.”24This took place on the second day. This is in accordance with what Rav said: They were moist on the first day and congealed on the second day.