Concerning Chastity 31The Author Goes on with the Interpretation of the Same Passage.

If, then, the rivers of Babylon are the streams of voluptuousness, as wise men say, which confuse and disturb the soul, then the willows must be chastity, to which we may suspend and draw up the organs of lust which overbalance and weigh down the mind, so that they may not be borne down by the torrents of incontinence, and be drawn like worms to impurity and corruption. For God has bestowed upon us virginity as a most useful and a serviceable help towards incorruption, sending it as an ally to those who are contending for and longing after Zion, as the psalm shows, which is resplendent charity and the commandment respecting it, for Zion is interpreted "The commandment of the watchtower." Now, let us here enumerate the points which follow. For why do the souls declare that they were asked by those who led them captive to sing the Lord's song in a strange land? Surely because the Gospel teaches a holy and secret song, which sinners and adulterers sing to the Evil One. For they insult the commandments, accomplishing the will of the spirits of evil, and cast holy things to dogs, and pearls before swine, in the same manner as those of whom the prophet says with indignation, "They read the law without;" for the Jews were not to read the law going forth out of the gates of Jerusalem or out of their houses; and for this reason the prophet blames them strongly, and cries that they were liable to condemnation, because, while they were transgressing the commandments, and acting impiously towards God, they were pretentiously reading the law, as if, forsooth, they were piously observing its precepts; but they did not receive it in their souls, holding it firmly with faith, but rejected it, denying it by their works. And hence they sing the Lord's song in a strange land, explaining the law by distorting and degrading it, expecting a sensual kingdom, and setting their hopes on this alien world, which the Word says will pass away, where those who carry them captive entice them with pleasures, lying in wait to deceive them.