I'll share a snippet from Ben Stanhope's book (Mis) Interpreting Genesis:
The noun raqia in the Genesis passage, which I have been translating as “firmament,” occurs in its verbal form 11 times in the Old Testament and refers to “beating out,” “stamping out,” or “spreading” by pounding. Frequently, it is used with reference to metal.[152] For example, Exod 39:3 says, “They hammered out (raqa), gold sheets.” Num 16:39 says, “They hammered out plating for the altar.” Jer 10:9 uses the term to refer to plated silver. Similarly, in a language close to Hebrew called Phoenician, we find a cognate noun mrqa, which refers to a metal “platter” or “bowl.”[153]
In the third century BC, the Old Testament was translated by seventy Jewish scholars into a Greek Bible called the Septuagint. The Septuagint was important because it served as the primary Bible of the New Testament authors and early church. When these ancient Jewish scholars made this translation, they selected a very rare term for expressing the meaning of the word raqia. They picked the Greek word stereoma, which indisputably emphasizes firmness and solidity.[154] Addressing his fellow professional Bible translators in the Journal of Translation, the senior linguist John R. Roberts concludes from the linguistic data that “the Hebrew makes it explicit” that the biblical firmament—the raqia “should be conceived of as a solid dome with a surface.”[155] The Israeli scholar Nissim Amzallag, in the department of Bible, Archaeology, and Near Eastern Studies at the Ben-Gurion University of the Negev, believes the term raqia, “designates the firmament as a piece of metal.”[156] Interestingly, the verbal form of raqia is used in Job 37:18 to refer to the creation of the skies—comparing its creation to the cast bronze plates from which mirrors were hammered out in the ancient world. [157] Here is the passage in three of its most popular English translations:
ESV: “Can you, like him, spread out (tarqia) the skies, hard as a cast metal mirror?”
NASB: “Can you, with Him, spread out the skies, Strong as a molten mirror?”
NIV: “Can you join him in spreading out the skies, hard as a mirror of cast bronze?”
Some creationists attempt to translate this passage as referring to God spreading out the clouds, not the sky. However, the verb typically refers specifically to beating out metal and certainly does here where the context is pounding out a bronze plate. It doesn’t make much sense to compare the hardness of clouds to metal. Likewise, Clines points out that the “spreading” of clouds is an ongoing and daily occurrence that would tend to imply a repeated, ongoing action of the verb.[158] However, ancient mirrors were only “spread out” by hammering during their initial manufacture after casting. It therefore makes more sense that the verb refers to a single past action—the initial creation of the sky.[159]
It is important to emphasize that an association of the sky with metal is not unique to ancient Israel. Egyptologists have long known this idea is found in Egyptian texts and art.[160] An excellent recent study by Almansa-Villatoro in the Journal of Egyptian Archaeology emphasizes that the ancient Egyptians believed the sky was specifically made of iron as a container for the heavenly ocean upon which the sun daily sailed.[161] Undoubtedly, the Egyptians inferred this because meteors, which they assumed to be fallen pieces of the firmament, occasionally fell in their lands and were harvested for their precious iron long before the Iron Age. Archaeologists have discovered numerous Egyptian artifacts made of the celestial metal, such as a famed ornate dagger found in the folds of King Tut’s mummy.[162] The Egyptian name for iron (bia n pt) accordingly means “metal of heaven.”[163] A common theme in the Pyramid Texts (PT) speaks of the necessity for the Pharaoh to ascend to the afterlife by first “splitting” through the sky’s “metal” (i.e. PT 257). PT 469 and 584 similarly speak of the king forcefully pushing his way through the “iron door in the starry sky” and other texts liken this necessity for the king to break through the iron firmament to breaking out of an egg (PT 757, 669).[164] The primeval egg seems to have been related to the sky goddess Nut, whose name is sometimes spelled with an egg determinative and whose primary symbol was a water jar. Almansa-Villatoro cleverly recognized that the Egyptian sign used to write the noun iron (Gardiner sign N41—a containment of water) is also strangely used in writing terms relating to water and women. This is likely because, since very early in Egyptian thought, the sky goddess was intimately connected to iron—the “metal of heaven” and the great heavenly waters upon which the solar bark sails before its daily consumption and rebirth from the archetypal womb of the goddess.[165]
Amongst the ancient Sumerians along the Tigress and Euphrates rivers, scholars have noticed that multiple terms for iron and tin seem to etymologically contain the term for heaven—AN.[166] Accordingly, the Assyriologist Samuel Noah Kramer affirmed that for the Sumerians, “The earth was a flat disk surmounted in the shape of a vault. Just what this heavenly solid was thought to be is still uncertain; to judge from the fact that the Sumerian term for tin is ‘metal of heaven,’ it may have been tin.”[167] Comparison with the Egyptian term “metal of heaven” seems to strengthen this interpretation.[168]
The opening of a Sumerian text called Gilgamesh, Enkidu and the nether world speaks of a time when heaven was “separated” from earth—when the two were “divided” from each other. Indeed, it can virtually be inferred that “The idea of a separation of heaven and earth is present in all ancient Near Eastern mythologies.”[169]
[171] An inscription by the carver labels the image “heaven” and “earth.”[172] Likewise, a papyrus of the Aegean poet Sappho (c. 620-570 BC) refers to the dawn ascending into “the bowl.”[173]
A related concept we see in the Bible is that the firmament is visually comparable to some sort of blue stone. In Exodus 24, Moses, Aaron, and Israel’s elders ascend Mount Sanai. Verse 10 tells us that upon doing so, “they saw the God of Israel, and under his feet was pavement like lapis lazuli,[174] like the body of the heavens in clarity.”[175]
In Ezekiel 1 the raqia is said to be crystalline or ice-like in color. In a vision, Ezekiel sees God seated on his throne above the firmament upheld by cherubim whose four faces represent the cardinal quarters of the Babylonian compass.[176] The message of the vision is that God’s reign extends over the whole of the earth even though the Jews are sitting in exile in Babylon: And a form was over the heads of the living creatures: a firmament (raqia) like the fearful color of crystal…and there was a voice from over the firmament (raqia) which was over their heads…. And from over the firmament (raqia) which was over their heads was the form of a throne of lapis lazuli stone in appearance. And from up above, upon the likeness of the throne, was an image in the appearance of a man…and the appearance of amber…. This was the appearance of the likeness of the glory of the Lord. When I beheld it, I flung myself upon my face….
We know this passage is describing a representation of the sky because, as a noun, the Bible uses this word raqia 17 times across Genesis, the Psalms, Ezekiel and Daniel.[177] In every single other case, it refers to the sky.
Likewise, the context of this passage is Babylonian, and it is remarkably similar in its enthronement description to a Babylonian text depicting Marduk seated on his lapis lazuli throne over the solid lower heavens of Babylonian cosmology, similarly surrounded by the gleam of amber.[178] The view that the heavens are stone is stated point-blank in the religious texts of Israel’s neighbors. One Akkadian text reads: The Upper Heavens are luludanilu-stone. They belong to (the god) Anu. He settled the 300 Igigi (gods) inside. The Middle Heavens are saggilmud stone. They belong to the Igigi. Bel sat on the high [platform] inside, The Lower Heavens are jasper. They belong to the stars. He drew the constellations of the gods on them.[179] A different tablet repeats the same phrase about the lower heavens.[180] In these texts, we are told the undersurface of the sky looking up from the earth is Jasper—a glassy, often translucent type of chalcedony. The text is probably talking about a sky-blue variety known from Persia.[181] Upon this firmament, the stars are “drawn,” perhaps similar to the concept of them being literally “set in the firmament” in Gen 1:17.
I could draw on more resources. But it's pretty self explanatory why Job would identify the sky as being hard like cast metal.
It's a part of historical ancient Israelite context and cosmology.
And this is a well understood fact of Jewish interpretive history. There are lots of writings throughout history going back to times well before Jesus, with respect to the sky being of a solid nature. And it's found in the writings of early church fathers as well.
It's the historical context of the old testament, an ancient near east context.
There is a reason the KJV calls it the "Firm"- ament. King James got it right. Modern day YECs got it wrong. It's that simple.
