Likutei Moharan 8:4/ליקוטי מוהר"ן ח׳:ד׳

14. {“The wrath of a king is as messengers of death, but a wise man shall pacify it” (Proverbs 16:14).} Therefore, “But a wise man shall pacify it.” The lack [a person feels] results from his sins. As our Sages taught: There is no death without [there first being] transgression; nor suffering without sin, as in (Psalms 89:33), “I will punish their transgression with the rod, and their sin with plagues” (Shabbat 55a). Therefore, the tzaddik, who draws the ruach-of-life and provides wholeness [in place] of the lack, is capable of winning atonement for the sin. This stems from the great mercy and compassion of the Creator, blessed be His name. For He contracts Himself into being the ruach-of-life for the tzaddikim—i.e., that they will receive the ruach-of-life from the Torah and draw the ruach-of-life to the lack; and with this they atone the sins.

2{“God, God, Omnipotent, merciful and compassionate, erekh apayim (patient), with rav chesed (great kindness) and truth. He is notzer chesed (keeps [in mind] the deeds of kindness) l’alafim (for thousands [of generations]), forgiving of sin and rebellion and error. Cleansing sin…” (Exodus 34:6).} [The atonement of sin] corresponds to the Thirteen Attributes of Mercy: “God, God, Omnipotent, merciful and compassionate, erekh apayim ….” “Erekh apayim” is an aspect of ruach <-of-life>, in that [God] extends His breath—sighing over [man’s] lack.

3This is the meaning of “with rav chesed .” As we have said, a person receives the ruach-of-life from the tzaddik/ rav of holiness. He is RaV chesed ; the antithesis of Esav, the RaV of the husks, who is “reddish,” [from the side of] stern judgment. And this is, “and truth.” For the tzaddik receives the ruach-of-life from the Torah, which is called “the Torah of truth [that] was in his mouth” (Malakhi 2:6).

4And this is the meaning of, “He keeps [in mind] the deeds of kindness l’alafim.” [The word] “l’ALaFim” alludes to the ALuFey (tribal chiefs of) Esav, the RaVrevay Esav—they are the RaV of the husks. And this is, “notzer chesed.” “Chesed” corresponds to the rav of holiness. He “keeps” [in check] and mitigates the tribal chiefs of Esav, ravrevay Esav.

5And therefore, “[He is] forgiving of sin and rebellion.” For as a result of the ruach-of-life, the wholeness [in place] of the lack, that we draw from the tzaddik by sighing, sins are atoned. This is the meaning of, “… but a wise man shall pacify it”; which is, “forgiving of sin and rebellion.”