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)

8269. '[This is my God,] and I will establish a dwelling-place for Him' means that when He is within good, which originates in Himself, He will be as if in His heaven. This is clear from the meaning of 'a dwelling-place', when it has reference to Jehovah or the Lord, as good. The reason why 'the Lord's dwelling-place' means good is that all good has its origin in the Lord; thus good is the Lord's, so completely that one may say it is the Lord. When the Lord dwells within it He dwells within His Divinity. Nor can He dwell anywhere else, according to the Lord's words in John,

Jesus said, If anyone loves Me He keeps My word, and My Father loves him, and We will come to him and make Our home with him. John 14:23.

Good that springs from God is what 'loving the Lord and keeping His word' describes here; for good comes from love. 'With him', it says, 'They would make Their home', which means within good residing with him. The expression 'as in His heaven' is used because heaven is called God's dwelling-place; and it is called this because good, which originates in the Lord, exists there and constitutes heaven. The Lord is also within the individual person as in His heaven when He is within good there; for the heaven within a person is good, and through good a person is present with angels in heaven. From all this it is now evident that 'I will establish a dwelling-place for Him' means that when He is within good, which originates in Himself, He will be as if in His heaven.