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)

1734. Verse 20 And blessed be God Most High who has delivered your enemies into your hand; and he gave him a tenth of everything. 'Blessed be God Most High' means the Lord's Internal Man. 'Who has delivered your enemies into your hand' means victory. 'And he gave him a tenth of everything' means remnants gained from victory.