Ibid. — 'Let brimstone be scattered in his tabernacle.' 23. The sins of the flesh are rightly compared to stinking and burning brimstone. — What else is brimstone but fuel for fire? Yet it so nourishes the fire that it exhales a most grievous stench. What therefore do we understand by brimstone but the sin of the flesh? For while it fills the mind with perverse thoughts as with certain stenches, it prepares eternal fires for it; and while it spreads the cloud of its stench in the reprobate mind, it supplies, as it were, nourishment for the flames that follow against that mind. For that by brimstone the stench of the flesh is understood, the very narrative of sacred Scripture bears witness, which relates that the Lord rained fire and brimstone upon Sodom (Genesis xix, 24).
For when He had decreed to punish the crimes of its flesh, in the very manner of the vengeance He marked the stain of the guilt. For brimstone has stench, fire has burning. Since therefore they had burned with perverse desires out of the stench of the flesh, it was fitting that they should perish at once by fire and brimstone, so that from the just punishment they might learn what they had done through unjust desire. This brimstone, then, is scattered in the tabernacle of the wicked man as often as the perverse delight of the flesh holds sway in his mind. And because depraved thoughts unceasingly possess him and forbid him to bear the fruit of good work, it is rightly added: