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)

1165. In the Word 'Mizraim' or Egypt means knowledge, that is, various facts, by which people wish to probe into the arcana of faith and so confirm the false assumptions acquired in that way. 'Mizraim' also means simply knowledge, and so knowledge that is useful. This is clear not only from the places just quoted but also from very many others which would fill up page after page if they were all included. See Isaiah 19:1-end; Isaiah 30:1-3; 31:1-3; Jeremiah 2:18, 36; Jeremiah 42:14-end; Jeremiah 46:1-end; Ezekiel 16:26; 23:3; Ezekiel 29:1-end; Ezekiel 30:1-end; Hosea 7:11; 9:3, 6; 11:1, 5, 11; Micah 7:12 [NCBS: 7:15]; Zechariah 10:10-11; Psalms 80:8 and following verses.