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)

6905. 'And let us sacrifice to Jehovah our God' means thus the worship of the Lord. This is clear from the meaning of 'sacrificing' as worship in general, dealt with in 923, for in the Hebrew Church and subsequently among the descendants of Jacob all worship was linked to sacrifices. This may be recognized from the fact that sacrifices were offered daily, and many at every feast. They were also offered when people were to be admitted into priestly functions or were to undergo purification; and there were sin-offerings and guilt-offerings, as well as those made as a consequence of vows, and those that were free-will offerings. All this goes to prove that worship in general is meant by 'sacrifices'. As regards its being the worship of the Lord that is meant by 'sacrificing to Jehovah God', this is plainly evident from the consideration that the sacrifices did not represent anything other than the Lord and the Divine celestial and spiritual realities that derive from Him, 1827, 2180, 2805, 2807, 2830, 3519, and also from the consideration that in the Word none other than the Lord is meant by 'Jehovah God', see above in 6903. 'Jehovah' is used to mean His Divine Being, and 'God' to mean His Divine Coming-into-Being from that Divine Being, so that 'Jehovah' is used to mean the Divine Good of His Divine Love, and 'God' to mean the Divine Truth emanating from His Divine Good.