“I beg and entreat that each one of you reckon up in his conscience the results of his fasting. If he discovers that he has gained much, let him reckon it to his hard work; but if he has gained nothing, let him use the remaining time to gain goods through diligent fasting. As long as the festival lasts, let us not leave before we have exerted ourselves and acquired great gain, so we will not leave with empty hands. In this way we shall not forsake the reward of fasting, since we have endured the toil of fasting. For it is possible to endure even the toil of fasting and not receive the reward of fasting. How? When we abstain from food but do not abstain from sins; when we do not eat meat but devour the homes of the poor; when we do not get drunk from wine but become intoxicated by wicked desire; when we continue without food for the entire day but pass all of it a wonton spectacles. Recognize that we can endure the toil of fasting but not receive the recompense of fasting, when we attend the theaters of lawlessness.
What does the divine law say? “You have heard that God said to the ancients, ‘You shall not commit adultery!’ But I say to you that everyone who looks lustfully at a woman has already committed adultery with her in his heart.” Have you seen an adulterer perform? Have you seen a sin fulfilled? And worse yet, the adulterer who is not convicted and condemned by a human court for his adultery is held accountable by the divine tribunal, whose retributions are eternal. “Everyone who looks lustfully at a woman has already committed adultery with her in his heart.” Fasting eradicates not only the disease but also the root of the disease, and the root of adultery is wonton desire. For this reason, Scripture punishes not only the adultery but also the desire, the mother of adultery.”