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.

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

10635. 'And all the people in whose midst you are will see the work of Jehovah' means that all who accept the Word will acknowledge the Divine within it. This is clear from the representation of 'Moses' as the Word, dealt with in the places referred to in 9372, so that 'the people in whose midst he is' means the Church where the Word exists, thus all who accept the Word, for others do not acknowledge the Divine within it; and from the meaning of 'seeing the work of Jehovah' as acknowledging the Divine within it. It is self-evident that such things are meant, for all within the Church who lead a good life acknowledge the Divine within the Word. The reason why they do so is that a holy influence from heaven enters them when they read the Word, although they do not know that correspondences are the means through which it comes to them. Furthermore this influence which depends on correspondences is not detected except as a general feeling of holiness occupying the mind. The situation is different in the case of those who do not lead a good life; in their case the internal through which influences from heaven come is closed.