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)

863. 'Noah opened the window of the ark which he had made means a further state when the truths of faith appeared to him. This becomes clear from the final words of the previous verse, which state that 'the tops of the mountains appeared'. It becomes clear from the meaning of those words, and also from the meaning of 'a window', dealt with already in 655, as that which constitutes the understanding part of the mind, or what consequently amounts to the same, the truth of faith. It becomes clear too from the fact that this is the first glimmer of light. The same observation made already about that which constitutes the understanding part, namely the truth of faith, being meant by 'a window must be made here. It is this: No truth of faith can possibly exist unless it originates in good stemming from love or charity, just as nothing that truly constitutes the understanding exists unless it comes from the will. Take away the will and no understanding exists, as shown several times already. Take away charity therefore and no faith exists. But because man's will is nothing else than evil desire the Lord has miraculously taken steps to prevent that which constitutes the understanding part, which is the truth of faith, being immersed in his evil desire, and has separated the understanding part of man's mind from the will part by means of a certain go-between, namely conscience, to which charity is added by the Lord. Without this miraculous provision nobody could ever have been saved.