Musar על נדה 60:15

מוצא שפתיך תשמור ועשית כאשר נדרת לה' אלוקיך . This verse contains an allusion to the oath of loyalty to the Torah each soul is made to swear by the angel who taught it that same Torah while still in the mother's womb (Niddah 30b). The phrasing "keep your promise," presupposes that everyone has taken such a vow.

נפש כי תחטא וגומר או הודע אליו חטאתו . Both in the Zohar and in the Tzror HaMor much has been written about these verses (4,22-23). The words או הודע אליו חטאתו are understood to refer to pre-natal knowledge, information given to the soul of the person in question prior to his being born. These commentators compare the situation to Jeremiah 1,5: "Before I created you in the womb I selected you, etc." This proves that communication with man commences before he is born. His soul is exhorted to behave in a certain way once he is on earth. The subject is explained by Rabbi Simlai in Nidah 30: "While the embryo is in the womb of its mother it may be compared to a writing book folded over, his two hands at his sides, etc.. A light is lit near his head enabling him to view every corner of the globe. He is taught the entire Torah as we know from ויורני ויאמר לי יתמך דברי לבך, "He also taught me and said to me: 'let your heart retain my words'" (Proverbs 4,4). Another verse from scripture along similar lines is Job 29,4: ואומר בסוד אלוקה עלי אהלי, "When the secrets of G–d were in my tent," i.e. I was privy to the mystical aspects of Torah while still in the womb. The baby is not born until it has been made to swear to be a צדיק not a רשע. He is told that even though the whole world may describe him as a צדיק, he must still consider himself a רשע. He should remain aware of the purity of G–d and his angels, as well as of the purity of the soul he has been equipped with. He is warned that as long as he preserves the purity of his soul all is well and good, but should he fail to so preserve its purity, his soul will be removed from him. This is the gist of Rabbi Simlai's statement.

But as for the righteous man, if a man praises him, he will not be proud of this, because our Sages said, "Even if all the world says, concerning you, that you are righteous, be in your own eyes like a wicked man" (Niddah 30b). And they said, "If you have friends, some of whom praise you, and some of whom correct and rebuke you, love the ones that rebuke you, and hate the ones that praise you, for the ones that rebuke you are conducting you to life eternal, and those who praise you will rejoice in your misfortune even though they praise you" (Abot de R. Nathan, 29). And it is said, "And a flattering (smooth) mouth worketh ruin" (Prov. 26:28). Scripture has likened a smooth mouth to a smooth (slippery) path, for just as a man will fall and be thrust down if he walks upon a slippery path — as it is said, "The angel of the Lord thrusting them, let their way be dark and slippery" (Ps. 35:5-6) — so will a man be thrust down and fall by a smooth mouth, which is a flattering mouth filled with sin. And concerning this it is said, "May the Lord cut off all flattering lips, the tongue that speaketh proud things" (Ps. 12:4). He has cursed the smooth mouth, for with it a man destroys his friends, and he has also cursed the hard tongue that carries gossip which is the opposite of the smooth tongue.