On the question why certain Names in the Holy Scriptures are changed (236-240)

It is worth while, therefore, to examine what is meant by this purification which may be accomplished in three ways. Now it may almost be said that both offences and good actions are perceived to exist in three things; in intention, or in words, or in actions. On which account Moses, teaching in his hortatory admonitions that the attainment of good is not impossible nor even very difficult, says,

"It is not necessary to soar up to heaven, nor to go to the borders of the earth and sea, for the attainment of it, but it is near, yea, and very near." [*] And then in a subsequent passage he shows it all but to the naked eye as one may say, where he says, "Every action is in thy mouth, or in thy heart, or in thy hands:" [*] meaning under this symbolical expression, in thy words, or in thy designs, or in thy actions. For he means that human happiness consists in wise design, and good language, and righteous actions, just as the unhappiness arises from the contrary course.

For both well-doing and wrong-doing exist in the same regions, in the heart, or in the mouth, or in the hand; for some persons decide in the most righteous, and sagacious manner, some speak most excellently, some do only what ought to be done: again, of the three sources of error the most unimportant is to design to do what ought not to be done, the most grievous is to do what is iniquitous, the middle evil is to speak [*] [*] [*]

But it often happens that even what is least important is the most difficult to be removed; for it is very hard to bring an agitated state of the soul to tranquillity; and one may more easily check the impetuosity of a torrent than the perversion of the soul which is hurrying in a wrong direction, without restraint. For innumerable notions coming one upon the other like the waves of a stormy sea, bearing everything along with them, and throwing everything into confusion, overturn the whole soul with irresistible violence.

Therefore the most excellent, and most perfect kind of purification is this, not to admit into one’s mind any improper notions, but to regulate it in peace and obedience to law, the ruler of which principles is justice. The next kind is, not to offend in one’s language either by speaking falsely, or by swearing falsely, or by deceiving, or by practising sophistry, or by laying false informations; or, in short, by letting loose one’s mouth and tongue to the injury of any one, as it is better to put a bridle and an insuperable chain on those members.