והוא דבר גדול מאוד, כי אז ידע שעשה פעולה ביום זה, שברא מלאך אחד, ואם יש עליו מלאך מליץ אחד וגו' (איוב ל"ג כ"ג), וסימנך (קהלת ח׳:ה׳) שומר מצוה לא ידע דבר רע, היינו כשאדם מקבל על עצמו דבר זה להיות עומד על משמרתו מהבוקר עד ערב אולי יזדמן לו מצוה, וזהו שומר, מלשון (פ' וישב) ואביו שמר את הדבר, אזי הסגולה מזה הוא שלא ידע דבר רע, היינו שלא יבא לידי קרי הנקרא רע ח"ו, וסימנך (תהילים נ״ב:ג׳) חסד אל כל היום, היינו שבכל יום ויום צריך לעשות חסד לאל יתברך: (צוואת הריב"ש ד"ג ע"ב).
This is a very great thing. For then, a person knows that he did [a mitzvah] on that day, and created one angel – “And if there is for him an angel, an intercessor, one among a thousand5A thousand accusers. to vouch for a man’s uprightness, then He will be gracious to him, and say, ‘Deliver him from descending to the pit, I have found a ransom’” (Job 33:23). This is alluded to in [the verse]: “He who keeps (shomer) the commandment will not know an evil thing…” (Ecclesiastes 8:5). That is, when a person commits himself to being constantly attentive – from morning till eve – for a mitzvah to present itself to him. This is the meaning of shomer, as in “And his father watched out for the matter (shomar et hadavar)” (Genesis 37:11). Then, the result will be that he “will not know an evil thing.” That is, he will not have an improper seminal emission, which is called “evil,” G-d forbid.6The Torah considers the act of spilling seed as one of the most grievous sins possible, so much so that it is given the unique title of “evil” – ra. (As in the verse: “And Er, Judah’s first-born, was evil in the sight of G-d…” (Genesis 38:7), on which Rashi comments that he intentionally spilled his seed on the ground.) According to Kabbalah, this act was part of the sin of Adam, and causes damage even when it happens unintentionally, such as during sleep. Much of Chasidic thought deals with rectifying this sin on the personal and cosmic level. In addition to the mystical power of mitzvah observance to engender purity, the Baal Shem Tov may have meant that constant attentiveness to fulfilling the will of G-d protects a man from impure thoughts during the day, so that his dreams will be pure at night. This is as the Talmud states: “A person shouldn’t think about illicit things during the day that will bring him to impurity in the night” (Kesuvos 46a). This is alluded to in the verse: “The kindness of G-d is all the day” (Psalms 52:3). That is, each and every day, you must do kindness to G-d. Tzava’as HaRivash, p. 3b
והוא דבר גדול מאוד, כי אז ידע שעשה פעולה ביום זה, שברא מלאך אחד, ואם יש עליו מלאך מליץ אחד וגו' (איוב ל"ג כ"ג), וסימנך (קהלת ח׳:ה׳) שומר מצוה לא ידע דבר רע, היינו כשאדם מקבל על עצמו דבר זה להיות עומד על משמרתו מהבוקר עד ערב אולי יזדמן לו מצוה, וזהו שומר, מלשון (פ' וישב) ואביו שמר את הדבר, אזי הסגולה מזה הוא שלא ידע דבר רע, היינו שלא יבא לידי קרי הנקרא רע ח"ו, וסימנך (תהילים נ״ב:ג׳) חסד אל כל היום, היינו שבכל יום ויום צריך לעשות חסד לאל יתברך:
(צוואת הריב"ש ד"ג ע"ב).
This is a very great thing. For then, a person knows that he did [a mitzvah] on that day, and created one angel – “And if there is for him an angel, an intercessor, one among a thousand5A thousand accusers. to vouch for a man’s uprightness, then He will be gracious to him, and say, ‘Deliver him from descending to the pit, I have found a ransom’” (Job 33:23).
This is alluded to in [the verse]: “He who keeps (shomer) the commandment will not know an evil thing…” (Ecclesiastes 8:5). That is, when a person commits himself to being constantly attentive – from morning till eve – for a mitzvah to present itself to him. This is the meaning of shomer, as in “And his father watched out for the matter (shomar et hadavar)” (Genesis 37:11). Then, the result will be that he “will not know an evil thing.” That is, he will not have an improper seminal emission, which is called “evil,” G-d forbid.6The Torah considers the act of spilling seed as one of the most grievous sins possible, so much so that it is given the unique title of “evil” – ra. (As in the verse: “And Er, Judah’s first-born, was evil in the sight of G-d…” (Genesis 38:7), on which Rashi comments that he intentionally spilled his seed on the ground.) According to Kabbalah, this act was part of the sin of Adam, and causes damage even when it happens unintentionally, such as during sleep. Much of Chasidic thought deals with rectifying this sin on the personal and cosmic level. In addition to the mystical power of mitzvah observance to engender purity, the Baal Shem Tov may have meant that constant attentiveness to fulfilling the will of G-d protects a man from impure thoughts during the day, so that his dreams will be pure at night. This is as the Talmud states: “A person shouldn’t think about illicit things during the day that will bring him to impurity in the night” (Kesuvos 46a).
This is alluded to in the verse: “The kindness of G-d is all the day” (Psalms 52:3). That is, each and every day, you must do kindness to G-d.
Tzava’as HaRivash, p. 3b