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)

'Herb bearing seed,' as mentioned in Genesis 1:29, signifies truth in terms of its use. (Arcana Coelestia 57) Every herb in the Bible signifies some type of knowledge.

'Green herbs,' as mentioned in Genesis 1:30, mean food for the natural man.

'Eating the herb of the field,' as mentioned in Genesis 3:18, signifies that a person should live as a beast.

'Herb of the field' signifies spiritual truth.

(References: Arcana Coelestia 7626)