2. And lest it should seem that necessary Continence was to be hoped for from the Lord only in respect of the lust of the lower parts of the flesh, it is also sung in the Psalm; |Set, O Lord, a watch to my mouth, and a door of Continence around my lips.| But in this witness of the divine speech, if we understand |mouth| as we ought to understand it, we perceive how great a gift of God Continence there set is. Forsooth it is little to contain the mouth of the body, lest any thing burst forth thence, which is not for the better, through the sound of the voice. For there is, within, the mouth of the heart, where he, who spake these words, and wrote them for us to speak, desired of the Lord that the watch and door of Continence should be set for him. For many things we say not with the mouth of the body, and cry aloud with the heart: but there goes forth from the mouth of the body no word of any thing, whereof there is silence in the heart. Therefore what flows not forth thence, sounds not abroad: but what flows forth thence, if it be evil, although it move not the tongue, defiles the soul. Therefore Continence must be set there, where the conscience even of them who are silent speaks. For it is brought to pass by means of the door of Continence, that there go not forth thence that, which, even when the lips of the flesh are closed, pollutes the life of him that hath the thought.
Ps. cxli.3 c3. Lastly, to show more plainly the inner mouth, which by these words he meant, after having said, |Set a watch, O Lord, to my mouth, and a door of Continence around my lips,| he added straightway, |Cause not my heart to fall aside into evil words.| The falling aside of the heart, what is it but the consent? For he hath not yet spoken, whosoever in his heart hath with no falling aside of the heart consented unto suggestions that meet him of each several thing that is seen. But, if he hath consented, he hath already spoken in his heart, although he hath not uttered sound by the mouth; although he hath not done with hand or any part whatever of the body, yet hath he done what in his thought he hath already determined that he is to do: guilty by the divine laws, although hidden to human senses; the word having been spoken in the heart, no deed having been committed through the body. But in no case would he have moved the limb without, in a deed, the beginning of which deed had not gone before within in word. For it is no lie that is written, that |the beginning of every work is a word.| Forsooth men do many things with mouth closed, tongue quiet, voice bridled; but yet they do nothing by work of the body, which they have not before spoken in the heart. And through this since there are many sins in inward sayings which are not in outward deeds, whereas there are none in outward deeds, which do not go before in inward sayings, there will be purity of innocence from both, if the door of Continence be set around the inward lips.
Ps. cxli.4. [See R.V.] Ecclus. xxxvii.16. LXX.