805. 'Everything which had the breath of the spirit of life 1
in its nostrils' means people belonging to the Most Ancient Church who had the breath of life 1
in their nostrils, that is, the life of love and of faith deriving from love. This is clear from what has been stated already in 96, 97. Life is what the most ancient people meant by 'breath in the nostrils' or breathing, which is the life of the body corresponding to spiritual things, just as the motion of the heart is the life of the body corresponding to celestial things. Here because the subject is the people before the Flood who from what they inherited from their forefathers had within them seed from a celestial origin, though that seed had been annihilated or suffocated, the statement 'everything that had the breath of the spirit of life 1
in its nostrils' is used.
(Odkazy: Arcana Coelestia 96-97)
 These words also conceal something quite deeply hidden, which has been dealt with already in 97. It is this: The member of the Most Ancient Church possessed internal breathing, and so possessed breathing that accorded with and was similar to the breathing of angels, which will in the Lord's Divine mercy be described later on. The nature of that breathing varied according to every one of the states of the internal man; but it was altered in the process of time among their descendants down to this final generation of them in whom everything angelic perished. At that point they were no longer capable of breathing in company with the angelic heaven. This was the real reason for their annihilation, and why it is now said that 'they breathed their last' and that 'they died in whom there was the breath of the spirit of life 1
in their nostrils'. After those times internal breathing came to an end, and with it communication with heaven, and consequently celestial perception; and external breathing took its place. And since communication with heaven came to an end in this way, members of the Ancient or new Church were no longer capable of being celestial men, as the most ancient people had been, but spiritual. These matters however will in the Lord's Divine mercy be dealt with later on.
1. literally, of lives