הַֽ֭לְלוּהוּ שְׁמֵ֣י הַשָּׁמָ֑יִם וְ֝הַמַּ֗יִם אֲשֶׁ֤ר ׀ מֵעַ֬ל הַשָּׁמָֽיִם׃
לױבט אים, די הימלען פֿון די הימלען, און די װאַסערן װאָס איבער די הימלען.
Ibn Ezra
“The heavens” – with the definite article, to indicate that that it’s speaking of those [heavens] which are visible, and [“heavens”] are always plural. And it's possible that it means, "its domain" – the domain of each one. The meaning of “heavens” is heights and elevation, and thus it is in Arabic, which is primarily based on the Holy Tongue. There are also “heavens of heavens”, but there is no singular form, like rechayim [“millstones”] and tzohorayim [“afternoon”]. People of stature will understand these secrets. Now the Ga’on says that the earth is like a point, and the heavens are like a thread encompassing it, and after these two were created, were everything within them [created], like water and fire. Others have said that the water was included with the earth, and the wind with the heavens. According to my opinion, these heavens and earth are [identical to] the firmament and the dry land, for only one things was created on each day: on the first day, light; on the second day, the firmament; on the third day, plants; on the fourth day, the luminaries, of the fifth day, and on the sixth day, the living things. The psalm mentioned [above] bears witness. And it’s impossible for the line which surrounds to precede the point, or for the point to precede the line, so therefore did they say that the heavens and the earth were created simultaneously. Bearing witness is “I call to them, they stand up together” – Isaiah 48:13. Yet this proof is not [sufficiently] clear, for this is not the explanation of the verse, for how can He say “to them” when they are not!? And how can He call it tohu? Rather, its meaning is “I created them”, and at the time I call to them, they will both stand up before Me like servants to do My will”, as in “Your word is standing in the heavens” – Psalms 119:89. And afterwards he mentioned the earth, afterwards stating that both will arise to execute judgment as He commands them.
Shadal
"Let there be a firmament:" The Holy One, blessed be He, wanted to inform Israel that neither the sun nor anything else controls the rain, to bring it down or not to bring it down. Therefore, He told about the existence of the higher waters before the existence of the luminaries. "Firmament (rakiya):" [It is] a body that stretches out like a plate, [as in] the expression, "To the One that stretches out (rokea) the earth over the waters" (Psalms 136:6); "And they flattened (yiraka'au) the gold [into thin plates]" (Exodus 39:3); and [also] "And over the heads of the living creatures there was the likeness of a firmament, like the color of the terrible ice" (Ezekiel 1:22). And here it portrayed the air between the earth and the clouds as a body that extends and separates between the waters on earth and the waters in the clouds, and carries the waters upon it; and by the will of God, the water descends from there to the earth. And it is like it states (Deuteronomy 28:12), "And God will open for you His good storehouse, the heavens, to give the rain of your land in its time;" and in the Curse, when it states (Leviticus 26:19), "And I will give your skies to be like iron," to prevent the descent of water upon them; and so [too] below (Genesis 7:11), "and the windows of the heavens opened." But afterwards, in the time of Yishiyahu, it appears that they knew that there are no storehouses of water above, and that rain waters return above; since behold, he says (Isaiah 55:10), "For just as the rain and the snow come down from the skies, and do not return there except when the earth is satiated;" [which] implies that after it is satiated, it does return to there, see my commentary there. And so [too], Yirmiyahu said in the way of a question, "do the heavens give raindrops?" (Jeremiah 14:22); [which] implies that [the heavens] do not give them by themselves, since they do not have storehouses of water in them. And so [too], they called the vapors that rise up from upon the earth [and become clouds] the name, nissi'im (raised up ones), as [in], "He raises nissi'im from the end of the earth" (Psalms 135:7); "He raised the nissi'im from the end of the earth" (Jeremiah 10:13; 51:16); and so [too], "Nissi'im and wind, but no rain" (Proverbs 25:14). And we do not know from what time this word (nissi'im) became common; as Psalm 135 is not attributed to David and it is not clear that the Book of Proverbs from Chapter 25 is by Shlomo. And in Job, he says (Job 38:22), "Did you come to the storehouses of snow, did you see the storehouses of hail?" - and this is a proof of the antiquity of that book. And since the word, rakiya, is based on the belief in higher waters - "the waters that are above the heavens" (Psalms 148:4) - that the rakiya supports, and that belief became antiquated and forgotten; the word, rakiya, also became antiquated. And [rakiya] is only used to indicate the skies in three [other] places. Two are in Psalms - "and the acts of your hands, does the rakiya proclaim" (Psalms 19:2); "praise Him in the rakiya of His strength" (Psalms 150:1) - since the word remained in poetic use; as it is the custom in all languages for the poets to use antiquated words. And the third place is in Daniel 12:3, "And the enlightened ones will shine like the splendor of the rakiya;" and there also, it is a poetic expression. And so [likewise], in Malachi 3:10, "I will open for you the windows of the heavens," is by way of poetic expression. And we have also found a variant of rakiya referring to the heavens in Job 37:18, "Tarkiya (Did you spread out) the skies with Him;" and this too is a sign of the antiquity of this book. And he finishes [this verse], "they are as strong as a molten mirror," as they carry the weight of many waters. And so [too] did Shlomo say (Proverbs 8:28), "And in His strengthening of the skies above." And behold, the Torah spoke as in the language of people, and stated, "let there be a firmament," according to their thought (that it actually existed). And nonetheless, what was intended does not deviate from being true and solid, and that is that God implanted in the nature of water to rise upwards and to descend afterwards down to the earth. And in the Greek translation attributed to the seventy elders (the Septuagint), rakiya is translated as strauma, [which] is a matter of strength, and so [too] did they translate it afterwords into Latin [as] firmāmenta and this came to them from the use of the root, raka, in Syriac, which denotes strength; and so [too], rakiya in Syriac is strong and hard. And Johannes Clericus says that they translated it thus, because it was the opinion of some of the ancient philosophers that the heavens and air that surround the earth on all sides, prevent it and everything on it from getting detached and crumbling apart; and behold, they cause the earth to stay hard and its parts to remain fastened together. And he explains the expression to be one of hitting and trampling, as in "hit with your hand and stamp (reka) with your foot" (Ezekiel 6:11); "because you hit with your hand and you stamped (rakacha) with your foot" (Ezekiel 25:6); because the heavens are stamping on the earth and stopping its parts from detaching. And all of this is far from the simple meaning of the verses. And nonetheless, [his] words, that the origin of the root, raka, is from stomping and hitting, are plausible. And because something that is hit [becomes] flat and stretched out, the root, raka, is borrowed to indicate stretching out and flatness.
Chidushei Agadot
Between the upper waters and the lower waters: There are differing opinions about this: Some of them say that the firmament that divides between the lower and the higher waters are the planets, and that is the opinion of the Ramban. And he was prodigious in bringing many passages about the truth of this idea. And it is [also] the opinion of Rashi, may his memory be blessed, in his commentary on the Pentateuch. For he wrote (Rashi on Genesis 1:6:2), "'In the midst of the waters' - in the middle of the waters; because there is distance, etc." But the Rabbi of the Guide (Rambam in the Guide for the Perplexed) explained that the firmament is the place where the cloud exists. And at first glance, this statement of Ben Zoma only fits the explanation of the Rabbi of the Guide. And likewise did Re'em (R. Eliyahu Mizrachi) write about the verse, "in the midst of the water," and [Rashi's comment,] "in the middle of the waters, etc." And he wrote at length there: However that which is in Chagigah about Ben Zoma - that he said, "I was looking at the gap between the upper waters and the lower waters, etc. a mere three fingers"; and Rabbi Yehoshua said to his students, "Ben Zoma is still outside, etc." - he held that the firmament is speaking about the firmament of air (cloud). And the explanation [of the verse (Genesis 1:6)], "Let there be a firmament," is [hence,] there should be a firmament, like it sounds. And therefore they said that between the upper waters of the firmament and the lower waters, there is only three fingers according to the one, and like a hair's breadth according to the other. And from this, it is a wonder about [Rashi], may his memory be blessed, how he disregarded the Gemara and took hold of the words of Aggadah from Bereishit Rabbah. To here are the words of the Re'em. But in my opinion, this verse can fit with both explanations. For 'one thing God has spoken; two things have we heard.' For one verse can be expressed with several explanations. And from this, what Ralbag understood in the opinion of the Guide is incorrect and [these are his words]: And the Rabbi of the Guide already explained [that] the firmament is the place in which the cloud is found, since it was strange to him that water would be found above the frame of the heavens. To here [are his words]. For the [Rambam] also conceded this. And [the reason] he mentioned, air, and did not mention, the waters above the frame of the heavens, is because, waters, is only stated there as a metaphor. And a metaphor is from that which is different then the matter itself. And this is the explanation that Rabbi Akiva gave, "When you reach pure marble stones, do not say, 'Water,' as it is stated, 'He who speaks falsehood. etc.'" - like the Ralbag himself fully wrote. And both [opinions] are in the same [passage of] Scripture, "Praise the Lord from the Heavens, etc." (Psalms 148:1) - these are the heavens of the air. And afterwards, it is written (Psalms 148:4), "Praise Him, heavens of the heavens" - and these are the planets. And afterwards, it is written, "and the waters that are above the heavens." And so does the Re'em explain. And with this, it is explained [how] Rashi, may his memory be blessed, brought (Rashi on Genesis 1:8) in the explanation of [the word], heavens (shamayim), "Carry water (Sa mayim)" - and these are the words of Bereishit Rabbah; but afterwards, he wrote, "water is there (sham mayim)" - and these are the words of the Talmud, Chapter 2 in Chagigah (12a:19): "Rabbi Yosei bar Ḥanina said, 'Shamayim is sham mayim. It was taught in a baraita, 'Shamayim is esh oumayim (fire and water), since the Holy One, Blessed be He, brought them both, mixed them together and made the firmament with them.'" For these statements and their explanations do not contradict one another. Rather it is that the [statement in] Bereishit Rabbah mentioned there the matter of the waters above the planets and so it perforce explained that those heavens are sa mayim; since the waters are carried above by them. But our Talmud was speaking about the heavens of the air, like the statement of Ben Zoma. Perforce the explanation of those waters is sham mayim, because the agitation of the water is there. And so did the Re'em explain. And that which it said, esh oumayim, is because the heavens of the air are the place that the cloud comes to exist. And some of them are clouds of fire and some of them are clouds of water. As we have found, "and fire flashing in the midst of the hail" (Exodus 9:25), such that the hail and the fire were mixed together. Hence it is understood that these heavens were fire and water that the Holy One, blessed be He, mixed with one another. And the author of the Makor Chaim wrote like this idea regarding water and fire, that He mixed one with the other. And with this, there is no room for wondering why Rashi seized the words of the Aggadah and left over the words of the Gemara in Chagigah. As Rashi is not contradicting them. For if that was not so, he should not have brought the statement of Chagigah, "sham mayim," and "esh oumayim," since it is an explanation of the heavens of the air - as I have written. Rather he is explaining the verses with ideas that are close to its simple understanding. And this is the way of Rashi, may his memory be blessed, in several places - as the Re'em, may his memory be blessed, wrote in several places. However in the aggadot in the Yerushalmi in Berakhot (1:1:24), we say: It has been taught in the name of Rabbi Yehoshua, "The thickness of the sky is two fingers." The words of Rabbi Chanina disagree, as Rabbi Acha said in the name of Rabbi Chanina "'Spread the skies with Him; they are strong like a cast mirror' (Job 37:18) - 'spread,' teaches that they are made like sheet metal. I could think that they are not sturdy, that is why the verse says, 'strong, etc.'" To here are [its words]. And it is implied that it is speaking about the heavens that are the planets, and not the heavens of the air, for it is arguing there with one who holds that the width of the heavens is the distance of 500 [years]. And if so, according to this, it appears that it can be said that the statement of Ben Zoma, according to its simple meaning, is speaking about the waters above the planets. And the opinion of Ben Zoma - such that he said that the gap between the upper waters and the lower waters is a mere (two) fingers - is like the opinion of Rabbi Yehoshua there, that the width of the planets is two fingers. And that is what separates between the higher and the lower waters. And the one [here] who holds that it is like the width of a hair holds like Rabbi Chanina, that the width of the firmament that separates between them is only like sheet metal. And then there is no other way [to understand] the verse and Ben Zoma's statement besides the explanation of Rashi; and not that it is the firmament of the air, which is an approach that is far from the simple meaning of the verse. And the author of Yafeh Mareh wondered about the Re'em, and these are his [words]: And in my eyes, my studies should be separated from the like - how could he believe that our Rabbis, may their memory be blessed, explained, firmament, [to be] the air; and the upper and the lower waters in this way, etc.? See there, and this needs [further] study.