But many souls that have been in love with perseverance and temperance, when removed to a distance from the passions, have nevertheless withstood the power of God, and have undergone a change for the worse, while their Master has made a display of himself and of the work of creation; of himself, that he is always immovable, and of the work of creation, that it vibrates as if in a scale, and inclines opposite ways at different times. For Moses speaks to the Israelites of God, Who led ye then through that great and terrible wilderness, where there were biting serpents, and scorpions, and thirst; where there was no water? who brought forth for thee out of the hard rock a fountain of water? who fed thee with manna in the desert, which thy fathers knew not? Deuteronomy viii. 14. 
Do you not see that not only did the soul, while longing for the passions which prevailed in Egypt, fall under the power of the serpents, but that, also, while it was in the wilderness, it was bitten by pleasure, that affection of varied and serpent-like appearance? And the work of pleasure has received a most appropriate name, for it is called a biting. Moreover, not only they who were in the desert were bitten by serpents, but also they who were scattered abroad, for I, also, often having left the men who were my kinsmen and my friends, and my country, and having gone into the desert in order that I might perceive some of those things which are worthy of being beheld, have profited nothing. But my mind, being separated from me, or being bitten by passion, has withdrawn towards the things opposite to them. And there are times when in the midst of a multitude composed of infinite numbers of men, I can bring my mind into solitude, God having scattered for me the crowd which perplexes my soul, and having taught me that it is not the difference of place that is the cause of good and devil, but rather God, who moves and drives this vehicle of the soul wherever he pleases.
 Moreover, the soul falls in with a scorpion, that is to say, with dispersion in the wilderness; and the thirst, which is that of the passions, seizes on it until God sends forth upon it the stream of his own accurate wisdom, and causes the changed soul to drink of unchangeable health; for the abrupt rock is the wisdom of God, which being both sublime and the first of things he quarried out of his own powers, and of it he gives drink to the souls that love God; and they, when they have drunk, are also filled with the most universal manna; for manna is called something which is the primary genus of every thing. But the most universal of all things is God; and in the second place the word of God. But other things have an existence only in word, but in deed they are at times equivalent to that which has no existence.
 See now the difference between him who turns to sin in the desert and him who sins in Egypt. For the one is bitten by serpents which cause death, that is to say by insatiable pleasures which inflict death; but the other, he who meditates in the wilderness, is only bitten by pleasure and driven astray, but is not killed. And the one, indeed, is healed by temperance, which is the brazen serpent which was made by the wise Moses; but the other is supplied by God with a most beautiful draught to drink, namely, wisdom, from the fountain which He himself has brought forth out of his own wisdom.