Clement of Alexandria, whom we have found to be a rich source, is our next hunting-ground.
Protrepticus viii. fin.: "Hear again the prophet who says: The sun shall fail and the heaven shall be darkened, but the Almighty shall stand for ever: and the powers of the heaven shall be shaken, and the heavens shall be rolled up like a curtain, stretched out and pulled in (for these are the words of the prophecy), and the earth shall flee from the face of the Lord."
Many Biblical phrases are here, but the ensemble is not Biblical, and an Apocalypse of an Old Testament character does seem likely to be the source.
Protr. X. 98: "A certain prophecy says that things here (on earth) will be in an ill plight when they (men) put their faith in statues."
Pædagogus III. viii. 44. The expression "intelligent fire" (φρόνιμον πῦρ) is used. God "poured out a little of that intelligent fire" upon Sodom. It is a phrase which recurs in Clement and other writers, and which I believe we owe to some apocryphal book. It means a fire which distinguishes between the good and the bad.
The Pistis Sophia c. 115 speaks of "a very great, very vehement, wise fire which will burn up sins."
Clem. Alex., Eclogæ ex propheticis scripturis, 26: "The fire is conceived of as a good power and mighty, destroying the worse and preserving the better, for which reason this fire is called in the prophets intelligent." Cf. also 27.
Strom. vii. 34. 4: "We say that the fire sanctifies not the flesh but the sinful souls; we do not mean the all-devouring ordinary fire, but the intelligent, that penetrates the soul that passes through the fire."
Origen (on Prayer, 29): "Rather the retribution of their error takes place in them when they are delivered to sufferings of dishonour or cleansed by the intelligent fire, and in prison have the payment for every one of their shortcomings exacted from them to the uttermost farthing."
Origen (on Ezekiel, i. 3): "What, O Apostle, is that fire which tries our works? What is that fire so wise
