(ח) וַיִּקְרָ֧א אֱלֹהִ֛ים לָֽרָקִ֖יעַ שָׁמָ֑יִם וַֽיְהִי־עֶ֥רֶב וַֽיְהִי־בֹ֖קֶר י֥וֹם שֵׁנִֽי׃ {פ}
(8) God called the expanse Sky. And there was evening and there was morning, a second day.
(א) ויקרא אלהים לרקיע שמים. לא רצה ה' שיקרא בשם רקיע כי שם זה מורה על הפירוד והמחלוקת מלשון וירקעו פחי הזהב לרוקע הארץ. כי כל רקיע הוא מסך מבדיל בין שני דברים, ומטעם זה לא נאמר כי טוב בשני לפי שבו נברא המחלוקת, כי אין טובה כי אם במקום מציאת האחדות, ולכך נאמר בשלישי שתי פעמים כי טוב אחת למלאכת יום שלישי ואחת לגמר מלאכת המים שיש בו צד אחדות שנאמר יקוו המים אל מקום אחד ובעבור אחדות זה הזכיר כי טוב, אבל ביום ב' אשר ממנו יוצא כל שינוי והוא התחלה לכל שינוי ומחלוקת לא נאמר בו כי טוב ולא רצה ה' שיקרא בשם רקיע המורה על מסך מבדיל ובין אחים יפריד, ונקרא בשם שמים המורה על השלום כי שמים נגזר מלשון אש מים שעשו שלום ביניהם ונתחברו ונעשה מהם שמים והיינו שאמרו רז״ל (אבות ה יז) כל מחלוקת שהיא לשם שמים כו' ר״ל מחלוקת שתכליתו השלום כהוראת שם שמים וק״ל. ולפי פשוטו לא נאמר כי טוב בשני לפי שלא היה בו בריאה חדשה כי הרקיע כבר נברא ביום ראשון וטעם לדבר לפי שיום שני התחלה לכל שינוי ופירוד על כן לא רצה הקב״ה להטביע טבע השינוי בשום נברא.
The word mayim is a very closed word, with mems on both sides. Three different words, two of which are in the parsha Bereshit, change the meaning of the word mayim. The yud especially gives a sense of opening up the word. Through the seas being collected and the earth being dried, Hashem opens up the world to the possibility of life. A world that was covered completely with a water, a world that is described as tohu v'vohu, is opened up to the possibility of life slowly but surely in this parsha as order is made out of chaos.
Shamayim, the rekiah (firmament) adds the letter shin to the word mayim. This has been interpreted in various ways, to encompass esh and mayim, fire and water, as well as to encompass "carry water." When Hashem separated the waters by creating the firmament, He was separating the physical world from some other kinds of waters, the waters of fire and water. Is the Torah talking about literal waters above the firmament, or is it talking of some kind of metaphysical waters? The Torah also does not say that Hashem said this separation was good, so perhaps there is some negative quality to a separation between the skies and the lower waters.
The word damim does not appear in the parsha, literally it means bloods, but it is used to refer to bloodguilt. The dam of animals is mentioned as being non-kosher later in the Torah. Both blood and water (yamim) are connected to the physical life of animals, as well as human beings. The skies are connected to the spiritual existence, the uplifting toward Hashem, and the separation between the spiritual and physical.
This part of the Torah is the source for not eating a limb cut from a living animal. Here, dam refers to the spirit of the animal. Although the spiritual and physical waters are separated in this parsha, we can connect between them with our spirits.
Like the fence around our roof, the firmament/shamayim that Hashem created was a way to make the world ready for human habitation, separating the different waters (mayim) from each other so that the world could become prepared for humans to live in it. Both involve a form of separation during an act of creation.
(י) וַיִּקְרָ֨א אֱלֹהִ֤ים ׀ לַיַּבָּשָׁה֙ אֶ֔רֶץ וּלְמִקְוֵ֥ה הַמַּ֖יִם קָרָ֣א יַמִּ֑ים וַיַּ֥רְא אֱלֹהִ֖ים כִּי־טֽוֹב׃
יַמִּ֑ים is both the word for seas, mentioned in this parsha, and the word for days, as in the seven days of creation.
What does it mean to create day before the first day happened? What does it mean to separate darkness and light before the luminaries were placed in the sky. Perhaps what is going on here is Hashem's creation of the concept of time, and later where the luminaries were created refers to the sanctification of time.
The meaning of the Sabbath is to celebrate time rather than space. Six days a week we live under the tyranny of things of space; on the Sabbath we try to become attuned to holiness in time. It is a day on which we are called upon to share in what is eternal in time, to turn from the results of creation to the mystery of creation; from the world of creation to the creation of the world.
...There are no two hours alike. Every hour is unique and the only one given at the moment, exclusive and endlessly precious. Judaism teaches us to be attached to holiness in time; to learn how to consecrate sanctuaries that emerge from the magnificent stream of a year.
-Abraham Joshua Heschel
Water is the building block of much of Earth's creations. And also, the Torah is compared to water because of its essentiality to the existence of the world and the Jewish people.
The added letters from shamayim, yamim, and damim added to the word mayim spell one of the names of Hashem, SHA-DDAI when placed together. From the words of water, and the separations between the waters, the preparation of a space for human inhabitance, the uplifting of physical to spiritual, and the meaning-making of time, we can bring attention to some of the specialness with which Hashem embued our obligations on this earth, and mimic some of the order-making of the days of creation.
(כו) וַיֹּ֣אמֶר אֱלֹהִ֔ים נַֽעֲשֶׂ֥ה אָדָ֛ם בְּצַלְמֵ֖נוּ כִּדְמוּתֵ֑נוּ וְיִרְדּוּ֩ בִדְגַ֨ת הַיָּ֜ם וּבְע֣וֹף הַשָּׁמַ֗יִם וּבַבְּהֵמָה֙ וּבְכׇל־הָאָ֔רֶץ וּבְכׇל־הָרֶ֖מֶשׂ הָֽרֹמֵ֥שׂ עַל־הָאָֽרֶץ׃
This pasuk contains the words c'damut (which interestingly, contains the letters dam), yam, and shamayim, summing up my idea that we can learn from additions to the word mayim something about human existance. We can have dominion over the fish of the sea and birds of the sky and animals by keeping in check our own animal self.