A biblical word for the atmosphere around the earth. The original meaning of this word means space that is stretched out or expanded. The Hebrews considered the "firmament" as the empty sky where the clouds, sun, and moon were.
During the second day of Creation, God created the atmosphere above the earth. He did this to divide the waters under it from the waters above it. God called the firmament heaven (Genesis 1:6–8). The firmament provides an environment for the sun, moon, planets, and stars to exist and function as God made them to. On the fourth day of Creation, God created the lights in the firmament. They were to identify night and day and indicate the seasons. The greater light in the firmament, the sun, controlled the days, and the lesser light, the moon, controlled the nights (verses 14–19).
The word "firmament" is mentioned twice in the Psalms as the place of God’s handiwork (Psalms 19:1; 150:1). In the books of Ezekiel (Ezekiel 1:22–26; 10:1) and Daniel (Daniel 12:3), the firmament is always related to Creation.