In Genesis 8:21, this signifies that worship from charity and the faith of charity pleased the Lord. (Arcana Coelestia 924-925)

In Exodus 15:25, this signifies that truths became enjoyable. (Arcana Coelestia 8356)

'Sweet' signifies delightful things from the good of truth and the truth of good. Everything sweet in the natural world corresponds to delightful and pleasant things in the spiritual world.

(References: Apocalypse Explained 618)