In Leviticus 11:7 and Matthew 7:6, this signifies filthy loves of those in the hells of adulterers. (Apocalypse Explained 1044[4]) Swine signify people who love only worldly riches. (Apocalypse Revealed 727)

In Isaiah 65:4, this signifies appropriation of infernal evils. (Apocalypse Explained 659[2]) 'Swine' or 'hogs' correspond to the life of greed and its delight.

(References: Arcana Coelestia 1742)

In the Bible, things that are lower down, or under, physically, generally represent things that are lower or more external spiritually. In some cases, the lower things have been separated and put away to protect the good, but in others, it can mean that a less exalted idea or good desire is supporting a more exalted one.

(References: Arcana Coelestia 4564 [1-2], 8610, 9656)