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)

4632. On one occasion when I was thinking about the government of the soul within the body and about the influx of the will into actions, I noticed that those in the hell of excrement, which at that time had been opened for a short while, thought about nothing else than the soul's control of the anus and about the influx of the will into the voidings of excrement from there. This revealed the kind of sphere created by their perception in that hell and the stink produced by it. Something similar happened when I was thinking about conjugial love. In this case those in the hell where adulterers live were turning over in their minds nothing else than the kind of shameful acts and nasty practices that go with adultery. And when I was thinking about honesty, those given to deceit thought of nothing else but committing what was criminal by fraud.