Commentaria in Exodum
Note: This fire was produced by God, or rather by an angel, from air, or other matter near the bush; and inhered subjectively in that matter, not in the bush: for if the fire had been subjectively in the bush, the bush would have been turned into fire, and so corrupted and consumed. The angel, therefore, who was in the usual way here God’s minister, produced this fire naturally by applying active things to passive, or brought it from elsewhere; and fed and fostered it by applied sulphur, or other matter and fuel; and at the same time hindered it from acting on the bush, by inducing into the bush some viscous and very cold liquor or juice which would resist the fire, or rather the thin flame: for which reason some mountebanks are thought naturally to put their hands into molten lead, because they have first imbued their hands with such a liquor as resists the heat of the melted lead; or the angel did this in some other way and by natural cause. It can more easily be said, however, that God here suspended the action of fire, as I shall presently explain.
AND HE SAW THAT THE BUSH WAS ON FIRE, AND WAS NOT BURNT.—Properly the bush was not burning, but anyone who had seen it would have said it burned: for to burn is to scatter flame from itself; but the bush did not scatter flame, since this belongs to fire alone, which had not pervaded the bush so that it should be ignited: but contiguous only to the bush, so closely surrounded its branches and leaves that it seemed ignited and to vomit flames. For Holy Scripture often, especially in phenomena and apparent things, speaks of them not as they are in themselves on the part of the thing, but as they appear, or as men commonly judge and speak of them. So here the bush is said to burn, because to men ignorant of the secret of the thing and its cause it seemed to burn, and all who saw it would have said it burned. Add that it may be a synecdoche; for the bush is said to have burned because a part of the bush, namely the dry leaves of the bush, and the air mixed with the bush, were burning. For “bush,” as also “wood,” is called the whole complex; namely the whole aggregate of thorns, shrubs and trees, with the air and all other matter inserted and mixed in it. Now in this aggregate, though one part, namely the branches and green leaves, did not burn, yet the other, namely the air mixed here and there, stubble, stems and dry leaves, was burning. This seems to have been an illustrious miracle of God: God here preserved the substance of the fire; but hindered its action and burning (by withdrawing his concurrence), so that it should not touch the bush or its green leaves in the least, or dry up the bush. For with God not concurring with the fire to burn, not even all hell would have scorched a wisp of tow; for that axiom of Theologians is certain: no created thing can operate without the actual concurrence of God with another thing. In like manner God preserved the three children unhurt in the Babylonian furnace, and this is, says St. Basil on Psalm 28, what the Psalmist says: “The voice of the Lord divideth the flame of fire,” when with the pious, namely the three children just mentioned, he gave it the power of lighting, not of burning; but with the impious and the damned he gave it the power of burning, not of lighting: for the fire of hell does not illumine the damned but burns them, says St. Basil. Hence Philo rightly says: This bush seemed to be burned not by flame, but rather the flame itself to burn and be consumed; and the flame which is wont to burn the bush seemed here not to burn but rather to be burned and consumed by the bush.
You will ask, what does this fire, and the burning and unconsumed bush, signify literally?
I answer: This fire signified the Egyptians; the bush, the Jews: the fire burning and afflicting, but not consuming them: nay rather making them more splendid and stronger: for the bush is a weak and thorny shrub, wounding even by touch alone; but this remained unhurt by the fire, and was superior to it: which signifies that the present weakness of the Hebrews would be turned into great strength, and that they themselves through grave and many plagues, as through the thorns of a bush, would prick and sorely wound the Egyptians by whom they were then vexed (so Philo and Theodoret). The bush therefore, says Philo, cried out silently, both to the afflicted Hebrews and the afflicting Egyptians: “Do not succumb, O Hebrews! this your weakness is a power that will prick and scourge the Egyptians: those who desire to destroy you will unwillingly preserve you; you will escape so many evils unhurt, and when you seem most to be laid waste, then most will your glory shine forth. You also cruel ones, like a devouring fire, oppressors of the innocent (Egyptians), do not trust too much in your strength; think that your wealth, which you suppose invincible, will one day be destroyed; behold the flame, burning by its own nature, is itself burned as wood is; and the combustible wood burns after the manner of fire.”
You will ask secondly, what does this burning and unconsumed bush signify allegorically?
I answer: The fire in the bush is God in the flesh, or the Word made flesh. For the thorny bush, rough, humble and vile, signifies the humanity of Christ, which he of his own will subjected to many hardships and labours, took up poor, humble and despicable for the sake of our salvation; now as the fire did not consume the bush, so the deity did not consume the humanity, nor its mortality and weakness. “By the kindled bush,” says St. Gregory, book 28 Moral., chap. 1, “God speaking to Moses, what else did he show, but that from that people there would come one who in the fire of the Godhead would receive the sorrows of our flesh as the thorns of the bush; and would keep the unconsumed substance of our humanity even in the very flame of the divinity?” Hence also Cyril against Eutyches proves that two natures remained in Christ whole, unhurt and unconfused, as in this bush both bush and fire remained whole.
Again the fire in the bush, whatever Calvin may growl, is God conceived in the Blessed Virgin, and born of her, her virginity unhurt. So Theodoret, St. Bernard, serm. On the Blessed Mary, on that of Apocalypse 12: “A great sign appeared,” and Gregory of Nyssa, orat. On the Nativity of Christ: “As the bush,” he says, “kindles fire and is not burned: likewise the Virgin also bears light, and is not corrupted.” Hence the whole Church sings: “The bush which Moses saw unburnt, we acknowledge to be thy laudable virginity preserved, holy Mother of God.” Where note that virginity is aptly compared to the bush, because it must be preserved by humility and a rough and vile life: for in delicacies, as in pride, chastity is in danger.
Moreover St. Jerome, serm. On the Assumption: “The Blessed Virgin,” he says, “is the whitest wool, to which when the Holy Spirit had approached, as wool dyed with purple turns to purple, she herself too was turned into the mother of God, so that she is not what she already was.” She burned therefore with divine fire, as if kindled by the murex, and fenced about with glowing rays, she became a bush burning, unburnt: “The birth of salvation,” he says, “brought no corruption to virginal integrity; because it was the guard of modesty, the bringing forth of truth.”
Wherefore that Abbot who converted the harlot Porphyria, and incurred the suspicion of a crime committed with her, dying cleared himself of her by carrying fire in an unhurt garment, saying: “Believe, brethren, that as God kept the bush unburnt by fire, as these coals have not burned this my tunic, so neither have I known the sin of woman since I was born.” So it is in the Life of St. John the Almoner. So also St. Cunegund proved her chastity before her husband the Emperor Henry, by walking unhurt with bare feet over glowing iron. Moreover the Word of God in the bush is the Word of God on the cross, because in both among thorns. Hear Clement of Alexandria, book 2 Pedagogue, chap. 8: “That the Word, which had first been seen through the bush, he might show again through the thorn assumed, that all things are of one power, since the one Son of the Father is the beginning and end of the age.”
Note secondly, that fire aptly signifies the Godhead, and therefore God in the Old Testament everywhere appeared in the form of fire: and that first, because fire is the most subtle element; but God is a most pure spirit. Second, because fire is most luminous; but God is immense light, illuminating blessed minds, delighting the affection, and directing all acts of the Saints. Third, because fire is most hot; but God by his heat vivifies, purges, animates all things, nay, when he will, is angry, punishes, burns and lays waste with the zeal of his wrath. Fourth, because fire is lightest; but God dwells in the highest. Fifth, because fire is unmixed and most simple; such is God. See St. Dionysius, Celestial Hierarchy chap. 15, and St. Thomas on Isaias chap. 10. Hence the Persians worshipped fire as God, and the Chaldeans adored Ur, that is fire: the Romans also worshipped sacred fire, as Vesta.
Of this symbol of fire I shall say more Levit. 9, at the end.
You will ask thirdly, what does this fire in the bush signify tropologically?