The expanse (raqia) between the waters (Genesis 1:6–8)

Says God calls for a רָקִיעַ between the waters (Gen 1:6), makes it (1:7), and names it שָׁמָיִם, the noun rendered “heavens” in 1:1. The BSB uses “an expanse” and then “sky” for that noun and its name. Waters stand beneath it and above it (1:7). Lights are set “in the expanse of the sky” (1:14, BSB). Birds fly “in the open expanse of the sky” (1:20, BSB). The LXX has στερέωμα. See the Hebrew note, and the Greek note.

Uncertain What physical picture the word requires. No lean is taken here. (1) A solid dome, as in a common ancient picture of the world, which the text uses. Ground: waters above a structure the Greek calls firm, and the related verb of beating out or spreading out. (2) Sky or atmosphere, with the waters above as clouds. Ground: birds fly on its face (1:20), and the lights shine upon the earth (1:15, 17). (3) Language of appearance, with no commitment to a physical model. Ground: the text names and uses the expanse and does not describe its material.

Ancient Near Eastern pictures of the cosmos are background only; see the historical note. They do not fix the meaning.