32. Manifestly also in the Gospel we find the mouth of the heart: so that in one place the Lord is found to have mentioned the mouth both of the body and of the heart, where he saith, “Are ye also yet without understanding? Do ye not yet understand, that whatsoever entereth in at the mouth, goeth into the belly, and is cast out into the draught? but those things which proceed out of the mouth come forth from the heart, and they defile the man. For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies: these are the things which defile a man.”55    Matt. xv. 16–20 Here if thou understand but one mouth, that of the body, how wilt thou understand, “Those things which proceed out of the mouth, come forth from the heart;” since spitting also and vomiting proceed out of the mouth? Unless peradventure a man is but then defiled when he eateth aught unclean, but is defiled when he vomits it up. But if this be most absurd, it remains that we understand the mouth of the heart to have been expounded by the Lord, when He saith, “The things which proceed out of the mouth, come forth from the heart.” For being that theft also can be, and often is, perpetrated with silence of the bodily voice and mouth; one must be out of his mind so to understand it as then to account a person to be contaminated by the sin of theft, when he confesses or makes it known, but when he commits it and holds his peace, then to think him undefiled. But, in truth, if we refer what is said to the mouth of the heart, no sin whatever can be committed tacitly: for it is not committed unless it proceed from that mouth which is within.

32. Manifeste etiam in Evangelio invenimus os cordis; ut uno loco et corporis et cordis os Dominus commemorasse inveniatur, ubi ait: Adhuc et vos sine intellectu estis? Non intelligitis quia omne quod in os intrat, in ventrem vadit, et in secessum emittitur; quae autem procedunt de ore, de corde exeunt, et ea coinquinant hominem? De corde enim exeunt cogitationes malae, homicidia, adulteria, fornicationes, furta, falsa testimonia, blasphemiae: haec sunt quae coinquinant hominem (Matth. XV, 16-20). Hic si unum os, quod est corporis, intellexeris, quomodo intellecturus es, Quae autem procedunt de ore, de corde exeunt; cum et sputus et vomitus de ore procedant? Nisi forte tunc quisque non coinquinatur, cum edit aliquid immundum; coinquinatur autem, cum id evomit. Quod si absurdissimum est, restat ut os cordis intelligamus a Domino expositum, cum ait, Quae procedunt de ore, de corde exeunt. Nam et furtum cum possit, et saepe ita fiat, in silentio corporalis vocis atque oris perpetrari; dementissimum est sic intelligere, ut tunc putemus quemquam peccato furti contaminari, cum id fatetur aut indicat; cum autem id tacite committit, incoinquinatum arbitrari. At vero si ad os cordis quod dictum est referamus, nihil omnino peccati tacite committi potest: non enim committitur, nisi ex ore illo interiore procedat.