מִ֭בְּכִי נְהָר֣וֹת חִבֵּ֑שׁ וְ֝תַעֲלֻמָ֗הּ יֹ֣צִא אֽוֹר׃ (פ)
Ele tapa os veios d`água para que não gotejem; e tira para a luz o que estava escondido.
Rashi
נבכים הם means, shut up and sunk deep. old French serrer. Of similar meaning are (Job 38:16) “the depths of (נבכי) the sea”; (Psalms 84:7) “in the vale of dejection (הבכא)”; (Job 28:11) “from the depths (מבכי) of the rivers.”
Radak
ויהי מבדיל בין מים למים, the meaning of these words is similar to the words בין המים אשר מתחת לרקיע ובין המים אשר מעל לרקיע, “between the waters which are below the atmosphere and the waters which are above the atmosphere.” (end of verse 7). These “upper” waters are normally something that exist only as a potential, awaiting the rising of vapours from the lower waters (oceans) i.e. moist air, to transform them into actual water, i.e. rain, as has been explained by the scientists. The “separation” was needed in order for the upper “waters” to retain the ability to be converted into actual waters as they had been prior to the separation. Only in this fashion would it become possible to also irrigate the high mountains on the surface of the earth.
Personally, I am perplexed by what Maimonides wrote in his Moreh, page 235 of Rabbi Kapach’s edition, He compared the separation described here to the separation that G’d had made between light and darkness. How could this be, seeing that here the division is between what is “up,” on top, and what is “down,” below. The division was not a natural division, separation, such as that between light and darkness. How could Maimonides describe “this” division as טבעי, i.e. in the very nature of things? Still, the fact remains that Maimonides is correct, and he has enlightened us who had been walking in darkness, just as he has enlightened us concerning many other things. It is worthwhile to examine what our sages of old have written on this and how their understanding agrees with the result of the researches of the scientists in our time. (14th century)
We read in Bereshit Rabbah 4,2 (a comment attributed by different scholars to two different authors) “at the time G’d said: “let there be an atmosphere within the waters,” the innermost drop of water froze (congealed) becoming what are known as the “lower” regions of heaven, as opposed to שמי השמים, the name by which the “upper” celestial regions are known. Rav says that whereas on the first day the heavens were in a wet, fluid state, they congealed on the second day. The words: יהי רקיע are a directive for this atmosphere to become strong; [to assume firm contours. Ed.] Rabbi Yuda in the name of Rabbi Seymon says that these words mean: יעשה מטלית לרקיע, “let the heaven be equipped with a cover.” The word is used in the same sense as in Exodus 39,3 וירקעו את פחי הזהב, “they beat the gold plates into thin plates.” Rabbi Chaninah said that a fire issued forth from above and lapped up the wet parts of the Rakia, thereby solidifying the remainder. When Rabbi Yochanan encountered the verse ברוחו שמים שפרה in Job 26,13, “By His spirit the heavens were calmed,” he used to say that Rabbi Chaninah had interpreted our verse correctly. Rabbi Yudan, son of Rabbi Shimon, would say that a fire issued forth from the upper regions and dried out the moisture of the Rakia by means of its heat. Rabbi Tanchuma (Bereshit Rabbah 4,3) said if the Torah had written the words ובין המים אשר על הרקיע, I would have said that the reference was to the substance of the rakia. Seeing that the Torah wrote אשר מעל לרקיע, this refers to the “upper waters” which had been suspended there by a Divine directive. Rabbi Acha added that the “fruit,” i.e. derivatives of the upper waters are the rains which earth receives from these regions. The sages said also that that the upper waters did not separate voluntarily from the lower waters but that they cried. We know this from Job 28,11 מבכי נהרות חבש indicating that the rain descends in droplets, similar to tears. All of this basically conforms to what we have written earlier. The sages (Bereshit Rabbah 4,5) said also that the rakia is comparable to a pool which is covered with a ceiling. Due to the evaporation of the waters in the pool rising, the ceiling appears to break out in perspiration, releasing heavy drops of moisture. These drops of moisture are not salty (as the ocean water below), and they do not mix with the ocean water. This mysterious phenomenon is what is referred to in Pirkey de Rabbi Eliezer chapter 4 where we are told that in answer to the question which rakia was created on the second day? Rabbi Eliezer says that it was the rakia which is above the chayot [a category of certain angels and their habitat Ed.] seeing that we read in Ezekiel 1,22 ודמות על ראשי החיה רקיע, and there was a likeness above the chayoh resembling the rakia.” These “chayot” are not physical, do not possess a body.
Personally, I am perplexed by what Maimonides wrote in his Moreh, page 235 of Rabbi Kapach’s edition, He compared the separation described here to the separation that G’d had made between light and darkness. How could this be, seeing that here the division is between what is “up,” on top, and what is “down,” below. The division was not a natural division, separation, such as that between light and darkness. How could Maimonides describe “this” division as טבעי, i.e. in the very nature of things? Still, the fact remains that Maimonides is correct, and he has enlightened us who had been walking in darkness, just as he has enlightened us concerning many other things. It is worthwhile to examine what our sages of old have written on this and how their understanding agrees with the result of the researches of the scientists in our time. (14th century)
We read in Bereshit Rabbah 4,2 (a comment attributed by different scholars to two different authors) “at the time G’d said: “let there be an atmosphere within the waters,” the innermost drop of water froze (congealed) becoming what are known as the “lower” regions of heaven, as opposed to שמי השמים, the name by which the “upper” celestial regions are known. Rav says that whereas on the first day the heavens were in a wet, fluid state, they congealed on the second day. The words: יהי רקיע are a directive for this atmosphere to become strong; [to assume firm contours. Ed.] Rabbi Yuda in the name of Rabbi Seymon says that these words mean: יעשה מטלית לרקיע, “let the heaven be equipped with a cover.” The word is used in the same sense as in Exodus 39,3 וירקעו את פחי הזהב, “they beat the gold plates into thin plates.” Rabbi Chaninah said that a fire issued forth from above and lapped up the wet parts of the Rakia, thereby solidifying the remainder. When Rabbi Yochanan encountered the verse ברוחו שמים שפרה in Job 26,13, “By His spirit the heavens were calmed,” he used to say that Rabbi Chaninah had interpreted our verse correctly. Rabbi Yudan, son of Rabbi Shimon, would say that a fire issued forth from the upper regions and dried out the moisture of the Rakia by means of its heat. Rabbi Tanchuma (Bereshit Rabbah 4,3) said if the Torah had written the words ובין המים אשר על הרקיע, I would have said that the reference was to the substance of the rakia. Seeing that the Torah wrote אשר מעל לרקיע, this refers to the “upper waters” which had been suspended there by a Divine directive. Rabbi Acha added that the “fruit,” i.e. derivatives of the upper waters are the rains which earth receives from these regions. The sages said also that that the upper waters did not separate voluntarily from the lower waters but that they cried. We know this from Job 28,11 מבכי נהרות חבש indicating that the rain descends in droplets, similar to tears. All of this basically conforms to what we have written earlier. The sages (Bereshit Rabbah 4,5) said also that the rakia is comparable to a pool which is covered with a ceiling. Due to the evaporation of the waters in the pool rising, the ceiling appears to break out in perspiration, releasing heavy drops of moisture. These drops of moisture are not salty (as the ocean water below), and they do not mix with the ocean water. This mysterious phenomenon is what is referred to in Pirkey de Rabbi Eliezer chapter 4 where we are told that in answer to the question which rakia was created on the second day? Rabbi Eliezer says that it was the rakia which is above the chayot [a category of certain angels and their habitat Ed.] seeing that we read in Ezekiel 1,22 ודמות על ראשי החיה רקיע, and there was a likeness above the chayoh resembling the rakia.” These “chayot” are not physical, do not possess a body.
Rabbeinu Bahya
A Midrashic approach tinged with kabbalah: G’d had concluded a covenant with the waters in the “lower” regions of the universe .at the time these waters were separated from the “upper” waters (Genesis 1,7) that on Sukkot some of these waters laced with salt would be used as a libation on G’d’s altar. This is confirmed by Bereshit Rabbah 5,5 according to which the “lower” waters were called “crying waters” as they accepted the separation from the upper waters only after shedding salty tears. This is reflected in Job 28,11: “He dammed up the streams because they cried so much.” Rabbi Abba said that these waters separated from the upper waters by crying. The reason they cried was that they were saying “woe to us that we did not merit to ascend to the celestial regions where we would be close to our Creator.” In fact they were so upset that they dared to split “the deep” and threatened to ascend with their intrinsic power. G’d became angry at them and forced them back to their realm. We know all this from Isaiah 43,16: “Who made a road through the sea and a path through mighty waters.” Nonetheless, G’d told the “lower” waters that seeing their revolt was motivated by their desire to be closer to Him, He would not allow the upper waters to commence with the song of praise to Him until they had obtained permission from the “lower” waters to do so. This has been confirmed in Psalms 93,4: “more majestic than the sounds of the mighty waters of the sea is the voice of the Lord on high.” What is it that these waters say in order to signify their consent? אדיר במרום ה', “the Lord is majestic on high.” Furthermore, G’d promised the “lower” waters that when the time would come for the Israelites to offer sacrifices to Him on the altar, these would be accompanied by both salt and water libations. We have another Midrash in which the (terrestrial) world is described as divided into one third desert, one third habitable, and one third ocean. The oceans said to G’d: “the desert merited that the Torah was given in it; the habitable parts of earth merited that the Temple was erected on them; what are we going to get?” G’d responded saying that in the future, in G’d’s own good time, the Jewish people would include both salt and water in the sacrificial rites
Rashi
and they have become entangled by the thickening smoke. They shall become entangled and hemmed in by the strength of the conflagration. Every expression of entanglement has only בך as its radical. Comp. (Job 28:11) “From the recesses (מִבְּכִי) of the rivers”; (Psalms 84:7) “The valley of entanglement (הַבָּכָא).” And the ‘nun’ appears in it sometimes, and here an ‘aleph’ appears in place of the ‘nun,’ like the ‘aleph’ of אִבְחַת, “the howling of the sword” (Ezekiel 21:20), and the ‘aleph’ of וְאַחְוָתִי, “And my speech in your ears” (Job 13:17).