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.

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

The idea of a "prophet" is very closely tied to the idea of the Bible itself, since the Bible was largely written by prophets. At a lower level, prophets represent people who teach from the Bible. At a higher level, they represent the Lord as He reveals himself through the Bible. Viewed in a abstract way, prophets represent the holy parts of the Bible themselves, and also represent doctrine drawn from the Bible. The reason we say "largely written by prophets" and "the holy parts of the Bible" is that not all of the books currently included in the Bible have a complete and continuous internal sense. Some -- like Job, Ruth, and Song of Solomon -- are wonderful literary pieces that got included, but which lack the systematic meanings for words and phrases. Others -- the Acts and Epistles, primarily -- are really doctrinal works, the first attempt by others to extract meaning from Jesus' life and words.