In Leviticus 22:6, this signifies a state of being in falsities. (Arcana Coelestia 1666)

In Hosea 9:3, this signifies appropriating things impure and profane derived from reasoning. (Arcana Coelestia 4581[10], Apocalypse Explained 654[56]) 'Pollution' denotes the truth of faith defiled.

(Referencat: Arcana Coelestia 4504)

1666. That 'all [these] were gathered together at the valley of Siddim' means that they were immersed in the unclean things that go with evil desires becomes clear from the meaning of 'the valley of Siddim', dealt with below at verse 10, which says that 'the valley of Siddim was pits after pits of bitumen', that is, it was full of bitumen-pits, which mean the filthy and unclean things that go with evil desires, 1299. The same may be seen from the fact that Sodom, Gomorrah, Admah, and Zeboiim meant evil desires and false persuasions, which are by their very nature unclean. That they are unclean anyone inside the Church may see; and in the next life it is clearly seen in what happens there. Spirits such as are immersed in these unclean things desire nothing better than to spend their time in places full of stagnant water, mire, and excrement, so that their very disposition carries such things with it. The emanation of such unclean things from them is detected as soon as they come near the sphere of good spirits, especially when they desire to infest the good, that is, to band together and attack them. All this shows what is meant by the valley of Siddim.

[2] 'Which is the Salt Sea' means the foul things which accompany derivative falsities. This becomes clear from the meaning of 'the Salt Sea', which would seem to be the same place as 'the valley of Siddim', for the words used are 'the valley of Siddim, which is the Salt Sea'. But the latter phrase has been added for the reason that 'the Salt Sea' means the falsities that burst forth from evil desires; indeed not one such desire exists which does not produce falsities. The life belonging to evil desires may be compared to a coal fire, and the falsities to the dim light that comes from it. Just as fire cannot exist without light, neither can evil desire do so without falsity. Every evil desire stems from some filthy love, for that which is loved is desired and is therefore called desire, the desire itself containing within itself an extension of that particular love. And what favors or supports that love or desire is called falsity. This shows why the phrase 'the Salt Sea' has here been added to 'the valley of Siddim'.

[3] Since evil desires and falsities are what vastate a person, that is, deprive him of all the life belonging to the love of good and to the affection for truth, such vastation is described in various places as a salt region, as in Jeremiah,

He who makes flesh his arm will be like a bare shrub in the solitary place, and will not see when good comes; and he will inhabit the parched places in the wilderness, a salt land, and not inhabited. Jeremiah 17:5-6.

In Ezekiel,

Its swamps and its marshes are not healed, they will be given up to salt. Ezekiel 47:11.

In David,

Jehovah turns rivers into a wilderness, and the outgoings of waters into a dryness, a fruitful land into a salty waste because of the wickedness of those inhabiting it. Psalms 107:33-34.

In Zephaniah,

Moab will be like Sodom, and the children of Ammon like Gomorrah, a place abandoned to the nettle, and a saltpit, and a desolation for ever. Zephaniah 2:9.

[4] In Moses,

The whole land will be brimstone and salt, a burning; it will not be sown, and it will not sprout, nor will any plant come up on it, as at the overthrow of Sodom and Gomorrah, of Admah and Zeboiim. Deuteronomy 29:23.

'The whole land will be brimstone and salt, a burning' stands for goods and truths that have been vastated - 'brimstone' for the vastation of good, 'salt' for the vastation of truth. Indeed heat and saltiness are destructive of the land and its crops in the way that evil desire is destructive of goods, and falsity of truths. Since 'salt' meant vastation, it was also customary to sow the cities they had destroyed with salt, to prevent their being rebuilt, as in Judges 9:45. Salt is also used in the contrary sense to mean that which renders fertile, and that which so to speak adds flavor.

[1666a] Verse 4 Twelve years they served Chedorlaomer, and in the thirteenth year they rebelled.

'Twelve years they served Chedorlaomer' means that evils and falsities did not reveal themselves in childhood but were subservient to apparent goods and truths. 'And in the thirteenth year they rebelled' means the onset of temptations in childhood.