In the previous chapter the Alter Rebbe stated that sadness hinders one’s service of G‑d in general, and his battle with the Yetzer Hara in particular. He therefore discussed means of overcoming sadness caused by material concerns, and by anxiety over one’s sins.
In this chapter and the next, he will discuss another type of melancholy, that caused by concern over one’s sinful thoughts and desires. This category itself may be further subdivided into two: (1) Where these thoughts occur while one is occupied with his material affairs, and (2) Where these thoughts disturb his service of G‑d in Torah study, prayer and the like.
In this chapter the Alter Rebbe discusses the first situation. He states that not only are these thoughts no cause for sadness, but on the contrary, they ought to give rise to joy.
ואם העצבות אינה מדאגת עונות, אלא מהרהורים רעים ותאוות רעות שנופלות במחשבתו
If, however, his sadness does not stem from anxiety over sins that he has committed, but from the fact that sinful thoughts and desires enter his mind, then:
הנה אם נופלות לו שלא בשעת העבודה, אלא בעת עסקו בעסקיו ודרך ארץ וכהאי גוונא
If these thoughts occur to him not during his service of G‑d, but while he is occupied with his own affairs and with mundane matters and the like,
אדרבה יש לו לשמוח בחלקו, שאף שנופלות לו במחשבתו הוא מסיח דעתו מהם
he should, on the contrary, be happy in his lot; for although these sinful thoughts enter his mind, he averts his attention from them.
It is clear that here we are speaking of one who does not wilfully dwell on sinful thoughts, for if he does so he is a sinner, and the previous chapter has already dealt with sadness arising from sins.
לקיים מה שנאמר: ולא תתורו אחרי לבבכם ואחרי עיניכם אשר אתם זונים אחריהם
By averting his mind from sinful thoughts he fulfills the injunction, “You shall not follow after your heart and after your eyes, by which you go astray.”
Only when sinful thoughts enter one’s mind can he fulfill this command. For the intention of the verse is not that one be at a level where such thoughts would not occur to him: this is the level of tzaddikim, who have eradicated all evil from their hearts. Surely, then this verse is not addressed to tzaddikim. The verse refers rather to one who does have such thoughts, and he is commanded to banish them — as the Alter Rebbe continues:
ואין הכתוב מדבר בצדיקים לקראם זונים, חס ושלום
The above verse surely does not speak of tzaddikim, referring to them (G‑d forbid) as “going astray,”
אלא בבינונים כיוצא בו שנופלים לו הרהורי ניאוף במחשבתו, בין בהיתר כו׳
but of Beinonim like himself, in whose mind there do enter erotic thoughts, whether of an innocent nature [or otherwise],
וכשמסיח דעתו, מקיים לאו זה
and when he averts his mind from them, he fulfills this injunction.
ואמרו רז״ל: ישב ולא עבר עבירה, נותנים לו שכר כאילו עשה מצוה
Our Sages have said: “When one passively abstains from sin, he is rewarded as though he had actively performed a mitzvah.”
ועל כן צריך לשמוח בקיום הלאו כמו בקיום מצות עשה ממש
Consequently, he should rejoice in his compliance with the injunction just as he does when performing an actual positive precept.
Thus not only should the occurence of these thoughts not grieve him, but it ought to bring him joy, for only thereby is he able to fulfill this commandment.