Musar su Salmi 19:8

... And on this the Torah says (Exodus 13:7) "there will not be seen and there will not be found" - it will not be seen b'maaseh (in action) and will not be found b'machshava (in thought), rather one should anul it in his heart. The mitzvot have 3 categories: mitzvot of speech, of the heart and of action, as it is written (Deuteronomy 30:14) "in your mouth and in your heart to do it". Comes the Torah (instructing us) to anul it in the heart, corresponding to the mitzvot which are dependent on the heart. Comes the 'kabbalah' (instructing us) to eradicate it from the house or to burn it, corresponding to the mitzvot of action. And to say 'kol chamira', corresponding to mitzvot of speech. In this way the 3 categories of mitzvot are fulfilled through the prohibition of chametz, teaching you that the prohibition of chametz incorporates all the mitzvot... Just as the 'kabbalah' comes (instructing us) to eradicate chametz and (livdok) to check the house in nooks and in cracks, so too we are obligated to search and check the chambers of our inner being for bad (machshavas) intentions and bad (hirhurim) thoughts. Just as bedikat chametz (checking for chametz) is not valid by sunlight, nor by moonlight, nor by the light of a torch, but only by the light of a candle, so too the bedikah (checking) of the yetzer hara must be by the light of the neshama (soul) which is called 'ner' (candle), this is what is written (Proverbs 20:27) "the candle of Hashem is the soul of man, which searches the chambers of one's inner being.

And in Sifrei, Parshath Ekev we find (Mishlei 5:16): "'Then your springs [of Torah] will spread outwards': Words of Torah are compared to water. Just as water lives forever, so, words of Torah live forever, as it is written (Ibid. 4:2): 'For they are life to him who finds them, and to all of his flesh, healing.' And just as water raises the unclean one from his uncleanliness, so, words of Torah raise one from uncleanliness to purity, as it is written (Psalms 19:10): 'The fear of the L-rd is pure.' [And, just as water purifies a man, though the uncleanliness has spread through all of his limbs, so, Torah purifies a man from the uncleanliness of his sins, even if it has spread throughout him, from the soul of his foot until his head. And just as a man is not purified until the water rises over all of his limbs, and there be nothing intervening between his limbs and the water, so, he must subject all of his body and his limbs, in truth, to Torah, with nothing intervening, as it is written (Devarim 6:6): 'And these words shall be … upon your heart']. And just as water restores a man's soul, so do words of Torah restore a man's soul from the way of evil to the way of good, as it is written (Psalms 19:8): 'The Torah of the L-rd is complete, restoring the soul,.' And just as water is free for the world, so is Torah free for the world, as it is written (Isaiah 55:1): "Ho! all who are thirsty, go to the water [of Torah]." Lest you say: 'Just as water has no valuation, so, Torah has no valuation; it is, therefore, written [to negate this] (Mishlei 3:15): 'It is more precious than pearls and all of your desires cannot be compared to it.'"

The commandments mentioned in this portion may be divided into three categories. They correspond to the three "pillars" that support the universe, i.e. תורה-עבודה-גמילות חסדים, Torah, service of the Lord and the dispensation of kind deeds. Torah is represented by commandments such as not to add or to deduct from them. In other words, we are ordered to preserve the שלימות, perfection, wholeness of the Torah. Philosophers have already said that it is part of the definition of perfection that one cannot add to it or detract from it. Perfection is indivisible. Torah is totally bound up with the great and Holy Name of G–d i.e. תורת ה' תמימה. I have elaborated on this in my treatise מסכת שבועות, section תורה אור. The Zohar, commenting on Exodus 3,15: זה שמי … זה זכרי, points out that the numerical value of י-ה+שמי=365, whereas the numerical value of ו-י+זכרי=248, together 613, i.e. the number of commandments in the Torah. G–d also describes Himself as אני ראשון ואני אחרון, "I am first and I am last," indicating total perfection.