But I saw that before day 1 God say the Earth was water and darkness into its depth?
Then it is clear that water existed on the earth before this firmament was created.
"Water" is our word. Think of the natural world and remember your chemistry. Also, please, remember that if God really did inspire, dictate or write Genesis 1, he was inspiring, dictating to, or writing for, Levantine bedouins 4000 years ago. They were the audience. Their minds had to grasp what was being said, which means that God, in his inspiration, had to limit himself to their vocabulary, things they understood, in their language.
What is "water" to an ancient Levantine bedouin? It is not di-hydrogen oxide. It is not the polar ice caps - those were unknown to the bedouin, and would not be recognized as "water".
Water was liquid, that which flowed clear. As I said, remember your chemistry. At ambient temperature, what visible things are liquid? Only one element, just one: mercury. And mercury does not sit around in pools on the surface, it has to be extracted from rocks using a process that was unknown in 2000 BC.
So right there you realize something: the RARITY of different types of liquid in the world. Sure, WATER is common, and visible - in the rain, in the rivers and in the sea - we need it to live. But besides water, what other LIQUID is visible to a bedouin? Blood: there's a word for that. Milk: there's a word for that. "Seed" - and that's not really a liquid. Wine. My point is that liquids, other than water are rare in nature. Today, with chemical processes and knowledge we have all sorts of chemical mixtures and and compounds that are liquids: none of these existed 4000 years ago.
Therefore, there is no word in the ancient bedouin Hebrew for "liquid". The word is "water", because water is the only liquid that existed in their world. Mixtures of water had their own name. Nothing else was liquid. Big bodies of water were "seas" (in English - the Hebrew word for this incorporates the pictograph "M" which, in its original form, showed waves and is the root pictograph in the Hebrew word that we translate as "water".
So, what you must realize when you read the bedouin and read "waters" and "water", that word does not simply mean H2O. We have imposed a precision on the word "water" that did not exist back then. Case in point: when mercury was discovered, and its peculiar property of binding with elements and releasing gold from rocks, it was dubbed "aqua regia": "royal water" - because it was a liquid that, when poured, caused gold to precipitate out. The point is that a liquid was "water" - aqua - even 2000 years after the Hebrews.
So, when you read of the original conditions, and you read the word "water", you have to remember that that is an English word that has acquired a specific chemical meaning that it did not have before recent centuries. WE distinguish between "water" and "liquid". To the ancient world those are the same words, and every particular sort of liquid has its own specific name. "Water" is the generic word for flowing liquid.
With that in mind, consider what the universe was on the FIRST day, before energy was created. Again, the Hebrew word "light" is a pictographic sentence "AWR" - OR - and is the root of "order". Energy, of course, brings light out of the chaos, and the only way that energy can be seen by the ancients was in the form of light, including firelight.
Further, remember that there is no Hebrew word for "earth" - the planet. The word we translate as "earth" is the Hebrew word "land". And "heavens" is skies.
So, in the beginning there was the land and the sky, and the land was invisible - there was nothing, no light, no energy, just the breath (spirit is breath) of God on the surface of the great deep.
So, then, what were the conditions? 96% or so of the universe is hydrogen. When hydrogen is clumped together at absolute zero - no energy, it has not been created yet - what is it? It is not a solid, because it lacks the structure to form crystals. The same is true of Oxygen and Nitrogen and Helium. At absolute zero, the gases are not solids, they are LIQUIDS, which is to say, WATER in ancient Hebrew.
We cannot retroject Water is H2O on the language of the bedouins. "Water" means "liquid", and before energy, that is what is described: a proto universe of elemental hydrogen, with the other elements dissolved in it and invisible, in darkness without energy. And they are clumped as an abyssal "sea" of liquid hydrogen: water.
Then God said "Energy Exist!" and it did, and that energy blasted into the elemental "water" the blob of liquid hydrogen with all of the rest dissolved in it, "tohu vavohu" - which is not "formless and void" - that's formalistic language. That phrase in Hebrew is playful. It should be translated as "higgledy-piggledy" - chaotic. The land was DISSOLVED into the abyssal sea. Then energy came, the water - which is to say the liquid hydrogen/oxygen/nitrogen/ everything else ball, activated with energy, attenuated, spread out, matter clumped, and "land" (solid elements) began to clump - these are your planets.
But where did the "light" go, the energy? It disappeared INTO the elements, which WERE at absolute zero but were not animated by internal energy.
The "firmanent" is another one of those words. The Hebrew bedouin word is "sheet", like the black goathair sheets that form the tents in which the bedouins live to separate them from the sky. If you ever go inside one on a sunny day (I have) you discover they are cooler and darker than the outside, but that the weave of the cloth leaves little gaps between the threads through which the light pokes - like stars in the dark night.
So on the second day, with light and the further attenuation of the abyssal sea, God stretched a sheet between the "waters" - the attenuating plasma of hydrogen in space, and the clump of water and dissolved solid elements below. And the continents emerged from the water.
Genesis is the formation of the planets as explained by the most brilliant of all astrophysicists using only the language of 4000 BC. It's true, but you have to translate the key words: "water", "light", land (NOT "Earth"), "seas", "sheet" (NOT "firmament") into modern terms for your modern, educated, scientifically precise mind to get it. It's not particularly hard to do, but it does require not being stubborn about things like "H20", "Earth" and "firmament" - which are, remember, ENGLISH words used to try to indicate to us what a Hebrew word is.
Take out the hocus-pocus, and you have a remarkably clear explanation of the physics of the Big Bang, in the language of cave men. And a pretty good indication of the overmind that was talking to them, because they were obviously not capable of knowing any of these things. It is difficult for us to see what God is saying in Genesis unless we retroject OUR highly precise language back to what the "cavemen" knew, and then try to express astrophysics using exclusively the language and familiar concepts of 4000 years ago. God had the patience to do that, and did a remarkable job, we might notice. Few humans have the patience to even attempt such a thing, and get annoyed when somebody (like me) tries to show it to them.
Anyway, there is your answer.