The "midst" of something in the Bible represents the thing that is most central and most important to the spiritual state being described, the motivation that drives everything else. In general this will be something we love or feel, because at the core of things we are what we love; our loves define us.

(References: Apocalypse Revealed 44, 90, 268; Arcana Coelestia 2252, 2940, 10153, 10365, 10557, 10635, 10641)

In Genesis 1:16, this signifies goods and truths, or, in the opposite sense, evils and falsities. (Arcana Coelestia 1808)

In Matthew 24:29, this signifies knowledge of faith which falls from heaven. (Arcana Coelestia 32, 1984[3])

'Stars' signify the knowledge of truth and good. 'Stars' are frequently mentioned in the Word, and always signify goods and truths, but in an opposite sense, evils and falsities. In the same way, they signify angels, or societies of angels, in the opposite sense, evil spirits and their bands. When they signify angels, or societies of angels, then they are fixed stars, but when they signify evil spirits and their fellowships, then they are wandering stars. 'The seven stars' in Revelation 1, denote the knowledge of everything pertaining to good and truth, and so every variety of good and truth.

(References: Apocalypse Revealed 51)