In Genesis 15:17, this signifies the thickest falsity. (Arcana Coelestia 1861)

In Genesis 19:28, this signifies the state of falsity from the state of evil within the church. (Arcana Coelestia 2456)

In Exodus 19:18, this signifies the appearance of heavenly good in the greatest obscurity. (Arcana Coelestia 8819)

'Smoke,' as in Exodus 20, signifies divine truth, or the Word in its external form.

'Smoke of a great furnace,' as in Revelation 9:2, signifies the falsities of lust streaming out from evil loves.

In Revelation 9:17, 'smoke' signifies the pride of self-ascribed intelligence.

'Smoke of her burning,' as in Revelation 18:18, signifies damnation as a result of adulterating and profaning the Word.

In general, 'smoke' signifies divine truth in extremes, because 'fire' which gives off smoke, signifies love. 'Smoke' also signifies the same thing as 'cloud' in many places.

(References: Apocalypse Explained 9 [2]; Apocalypse Revealed 674-1; Revelation 2, 4, 8, 8:4)