In Genesis 18:27, this signifies the humility of the Lord's human as to its quality. (Arcana Coelestia 2265)

In Exodus 9:8, this signifies lustful falsities excited by the presence of infesting spirits. (Arcana Coelestia 7519, Apocalypse Explained 962[8])

In Ezekiel 27:30, this signifies something condemned, because the fire from which they come signifies infernal love. (Apocalypse Explained 441)

In Jeremiah 6:26, this signifies mourning because of the destruction of good and truth in the church. (Arcana Coelestia 637[9])

(Riferimenti: Apocalypse Explained 1175)

2265. 'Behold now, I have undertaken to speak to my Lord, and I am [but] dust and ashes' means, it is clear, [the state of] humiliation as to what the human was in comparison. Reference to the Lord's state when in the human, or His state of humiliation, and to the Lord's state when in the Divine, or His state of glorification, has been made several times already. It has also been shown that in a state of humiliation He spoke to Jehovah as if to another, but in a state of glorification to His own Self, see 1999. Here, because 'Abraham', as stated, represents the Lord when in the human, it is said in that state that the human in comparison with the Divine is 'dust and ashes'. This also is why that state is called the state of humiliation. Humiliation arises from the self-recognition that by comparison one is such. By the human here it is not the Divine Human that is meant but the human He derived from the mother, which He utterly cast out and in its place put on the Divine Human. It is the former human - that from the mother - which is referred to here as dust and ashes. See what has been stated above in 2159.