2 Accordingly, as I have admonished you in my last sermon, take heed, those of you specially who are still children and have need of a milk diet, of turning a curious ear to men, who have found occasion for self-deception and the deceiving of others in the words of the Lord, “I have yet many things to say unto you, but you cannot bear them now,” in order to the discovery of that which is unknown, while you still have minds that are incompetent to discriminate between the true and the false; and most especially on account of the obscene lewdnesses which Satan has instilled, by God's permission, into unstable and carnal souls, for this end, that His judgments may everywhere be objects of terror, and that pure discipline may best manifest its sweetness in contrast with the impurities of wickedness; and that honor may be given to Him, and fear and modesty of demeanor assumed by every one, who has either been kept from falling into such evils by His kingly power, or been raised out of them by His uplifting hand.
Beware, with fear and prayer, of rushing into that mystery of Solomon's, where “the woman that is foolish and brazen-faced, and become destitute of bread,” invites the passers-by with the words, “Come and make a pleasant feast on hidden bread, and the sweetness of stolen waters.” For the woman thus spoken of is the vanity of the impious, who, utterly senseless as they are, fancy that they know something, just as was said of that woman, that she had “become destitute of bread;” who, though destitute of a single loaf, promises loaves; in other words, though ignorant of the truth, she promises the knowledge of the truth.
But it is bread of a hidden character she promises, and which she declares is partaken of with pleasure, as well as the sweetness of stolen waters; in order that what is publicly forbidden to be uttered or believed in the Church, may be listened to and acted upon with willingness and relish. For by such secrecy profane teachers give a kind of seasoning to their poisons for the curious, that thereby they may imagine that they learn something great, because counted worthy of holding a secret, and may imbibe the more sweetly the folly which they regard as wisdom, the hearing of which, as a thing prohibited, they are represented as stealing.
Source: Tractates on the Gospel of John (New Advent)