Musar do Przysłów 22:3

Thus the simpletons walk confidently, fall and are lost without having felt any prior fear. This is what scripture refers to: "the way of the wicked is as darkness; they know not at what they stumble" (Prov. 4:19), and "the clever one foresees the evil and hides himself, but the foolish commits transgression and is punished" (Prov. 22:3), and "[a wise one fears and departs from evil], but the fool transgresses and feels confident" (Prov 14:16). For they feel as secure as an edifice, and they fall before having any knowledge whatsoever of the stumbling block.

For after this has become clear to them and likewise after it has become clear to them that the means to perfection are good deeds and traits, they will certainly never consent to diminish these means or be lenient in them. Since, it has already become clear to them that if they diminish in these means or are weak in these means, not employing the full force necessary, they will not attain the true perfection. Rather, it will be reduced in proportion to their reduction in exerting themselves to the necessary extent, leaving them lacking in perfection which is a great calamity and great evil to them.

The pinnacle of this level called "fear of sin", one of the greatest levels, is when a man is constantly afraid and worried lest he have in his hand some trace of sin which obstructs him from the perfection that he is under duty to strive for.

Regarding this our Sages of blessed memory said: "this teaches each person is burned from the Chupa (canopy) of his fellow" (Bava Basra 75a). This [burning] does not refer to jealousy which falls only to people lacking in understanding as I will explain with G-d's help. Rather, it is due to seeing oneself lacking from the perfection that he was capable of attaining just as his fellow had attained it.

The type of fear and guarding of oneself which is appropriate is that which is based on the guidance of wisdom and reason. On this scripture says: "the clever man sees the evil and escapes but the fool continues through and is punished" (Mishlei 22:3).

On similar to this the sages said: "we do not assume any defect without cause" (Chulin 56b). And "a judge need be guided only by that which his eyes see" (Bava Batra 131a). This itself is the intent of the verse we brought earlier "the clever man sees the evil and hides himself" (Mishlei 22:3), which states only about escaping from the evil that one can see not of the evil which perhaps, possibly, may occur.

For even though he strives to conquer his evil inclination and to subdue his lusts, he will not change his nature because of this. He will not be able to remove bodily lust from his heart. He will at most be able to subdue it and be governed by wisdom instead of it. But nevertheless the darkness of the physical will inevitably do its work to entice and seduce him.

On possessing this trait David would rejoice saying: "I will wash my hands in Cleanliness and I will go around Your altar, O G-d" (Tehilim 26:6). For in truth, only he who is completely clean from any trace of sin or iniquity is fit to appear before the presence of the King, G-d. For without this, he has only to feel shame and disgrace before Him as Ezra the Scribe said: "O my G-d, I am ashamed and embarrassed to lift up my face to You [for our iniquities have increased over our head...]" (Ezra 9:6).