ולא כטעות העולם שטועים להוכיח מנפילת המחשבה זרה, מכלל שאין תפלתם כלום

This refutes a common error. When a foreign thought occurs to some people during prayer, they mistakenly conclude that their prayer is worthless,

שאילו התפלל כראוי ונכון לא היו נופלים לו מחשבות זרות

for if one prayed properly and correctly, so they mistakenly believe, no foreign thoughts would arise in his mind.

והאמת היה כדבריהם אם היתה נפש אחת לבדה, היא המתפללת והיא המחשבת ומהרהרת המחשבות זרות

They would be correct if there would be but one soul within a person, the same soul that prays being also the one that thinks and ponders on the foreign thoughts.

For in this case, if the G‑dly soul were truly immersed in the prayers, there would be no room within it for foreign thoughts.

אבל באמת לאמיתו הן שתי נפשות, הנלחמות זו עם זו במוחו של אדם

but in fact there are two souls, each waging war against the other in the person’s mind.

The mind is thus not only the battleground, but also the prize, the object of the battle between the two souls, for:

כל אחת חפצה ורצונה למשול בו ולהיות המוח ממולא ממנה לבדה

Each of them wishes and desires to rule and pervade the mind exclusively.

וכל הרהורי תורה ויראת שמים מנפש האלקית, וכל מילי דעלמא מנפש הבהמית

All thoughts of Torah and the fear of G‑d come from the G‑dly soul, while all thoughts of worldly matters derive from the animal soul.

Similarly in our case, thoughts of prayer are from the divine soul, while foreign thoughts stem from the animal soul. Thus, the occurence of a foreign thought during prayer is no indication of a fault in the prayer. In fact the opposite may be true, as the Alter Rebbe explained earlier with the analogy of two combatants.

But if there are indeed two separate souls, why should the extraneous thoughts of one interfere with the devotions of the other? — They would not interfere, answers the Alter Rebbe,

רק שהאלקית מלובשת בה

except that the G‑dly soul is clothed within it — within the animal soul.

Therefore the G‑dly soul cannot ignore foreign thoughts rising from the animal soul; and thus foreign thoughts disturb one’s devotion in prayer.

והוא כמשל אדם המתפלל בכוונה, ועומד לנגדו ערל רשע, ומשיח ומדבר עמו כדי לבלבלו

This is, to use an example, like a person who is praying with devotion, while facing him there stands a wicked heathen who chats and speaks to him in order to confuse him.

If the other’s intention were not to disturb him but merely, say, to ask him a question, then he could rid himself of the disturbance simply by responding to the questioner. But when the intention is to disturb his prayers, he will gain nothing by responding; if he answers one question, he will promptly be asked another.

שזאת עצתו בודאי שלא להשיב לו מטוב ועד רע, ולעשות עצמו כחרש לא ישמע

Surely the best advice in this case would be to answer him neither good nor evil, but rather to act as though he were deaf, without hearing.

ולקיים מה שכתוב: אל תען כסיל כאולתו, פן תשוה לו גם אתה

and to comply with the verse, 1 “Answer not a fool according to his folly, lest you too become like him.”

כך אל ישיב מאומה ושום טענה ומענה נגד המחשבה זרה

Just as in the analogy of the heathen who disturbs one during prayer, so too when foreign thoughts enter one’s mind while praying he should answer nothing at all, nor should he engage in argument against the foreign thought, i.e., he should not occupy himself with mental discussions on the best strategy for countering the foreign thought,

כי המתאבק עם מנוול מתנוול גם כן

for he who wrestles with a filthy person is bound to become soiled himself.

Similarly, in the process of fighting the foreign thought, one’s mind becomes filled and tainted by it. He should therefore not seek to grapple with it.

רק יעשה עצמו כלא יודע ולא שומע ההרהורים שנפלו לו, ויסירם מדעתו

Instead he should pretend not to know nor hear the foreign thoughts that occurred to him, should dismiss them from his mind,

ויוסיף אומץ בכח כוונתו

and strengthen still more the power of his concentration.

ואם יקשה לו להסירם מדעתו מפני שטורדים דעתו מאד בחזקה

If, however, he finds it difficult to dismiss them because they distract his mind with great intensity,

אזי ישפיל נפשו לה׳, ויתחנן לו יתברך במחשבתו לרחם עליו ברחמיו המרובים

then he should humble his soul before G‑d, and supplicate Him in his thought to have compassion upon him in His abundant mercies,

כרחם אב על בנים הנמשכים ממוחו, וככה ירחם ה׳ על נפשו הנמשכת מאתו יתברך

like a father who takes pity on his children who stem from his brain — and so too should G‑d be compassionate on his soul, which derives from G‑d’s “mind” — the attribute of Chochmah, as explained in ch. 2,

להצילה ממים הזדונים, ולמענו יעשה, כי חלק ה׳ ממש עמו

to rescue it from the2 “turbulent waters,” i.e., the thoughts which disturb the soul. This He should do for His own sake, since truly3 “His people is a part of the L-rd.”

In order that one should not incur Divine judgement as to whether he is worthy of G‑d’s compassion, the Alter Rebbe advises that one should beseech G‑d’s mercies for His own sake. Since the soul is “a part of G‑d,” in aiding the soul he actually helps Himself, so to speak. The question of whether one is deserving of such aid thus becomes irrelevant.

Another interpretation sees the words, “This He should do for His own sake…,” not as part of the worshiper’s plea, but as a guarantee: G‑d will certainly come to the aid of one who entreats Him, and certainly will “rescue his soul from the turbulent waters”; this is for His own sake, for the soul is veritably a part of G‑d.