Refining Good From Evil
בפסוק והותירך ה"א בכל מ"י כו' לטובה
On the verse, "And Hashem your God will make you abundant in all the work of your hand... for good" (Devarim 30:9).
The Sfas Emes opens with the verse promising that Hashem will make Bnei Yisrael abundant in the work of their hands for good, and he sets out to explain what this "good" means.
כי לעתיד יהי' מתוקן התערובת טו"ר ויהי' מתברר רק הטוב
For in the future to come, the admixture of good and evil will be set right, and only the good will be refined out.
He explains that the future blessing is the separating of good from evil, so that all that remains is purely good, with no mixture of bad clinging to it.
וזה כאשר שש על אבותיך שנא' בהם בכל מכל כל שלא שלט בהם יצה"ר כדאיתא בגמ' והטעימן מעין עוה"ב
And this is the meaning of "as He rejoiced over your forefathers" (Devarim 30:9), for regarding them it is said "in all," "of all," and "all" (referring to the blessings of Avraham, Yitzchak, and Yaakov), since the yetzer hara had no dominion over them, as the Gemara teaches, and Hashem gave them a foretaste of Olam Haba.
This refined state is compared to the Avraham, Yitzchak, and Yaakov, over whom the yetzer hara had no power, so that they already tasted something of Olam Haba in this world.
והותירך דכ' מה יתרון לאדם כו' תחת השמש אין לו לפי שהטבע מסתיר ומתערב פסולת במעשה האדם
"And He will make you abundant" — as it is written, "What advantage does a person have... beneath the sun?" (Koheles 1:3), implying that he has none, because nature conceals and admixes waste into the deeds of a person.
Right now Koheles teaches that man gains no lasting advantage from his toil "beneath the sun," because the physical nature of this world hides the good and mixes worthless waste into everything a person does.
אבל אחר התיקון יהי' יתרון לאדם בכל המעשים שהרי הקב"ה ברא את האדם להיות שליט בכל העולם
But after the rectification, a person will have an advantage in all of his deeds, for the Holy One, Blessed is He, created the human being to be a ruler over the entire world.
After the future rectification, however, a person's deeds will carry real, lasting advantage, since Hashem originally created the human being to rule over the whole world.
וכשהוא ישר כראוי משתתף הקב"ה במעשה ידיו כמ"ש ויהי נועם ה' כו' ומעשי ידינו כוננהו
And when he is upright as is fitting, the Holy One, Blessed is He, partners in the work of his hands, as it is written, "May the pleasantness of Hashem... be upon us, and establish for us the work of our hands" (Tehillim 90:17).
When a person acts straight and properly, Hashem Himself joins as a partner in his actions, which is the meaning of the prayer that Hashem establish the work of our hands.
לשוש עליך לטוב כו' כ' שש על אבותיך
"To rejoice over you for good..." — it is written "as He rejoiced over your forefathers" (Devarim 30:9).
He returns to the verse's phrase about Hashem rejoicing over us "for good," linking it back to how He rejoiced over the Avos.
שכל מעשיהם הי' תקונים גדולים בכל העולמות
For all of their deeds were great rectifications throughout all the worlds.
The reason their lives are the model is that every one of their deeds brought about great tikkunim that resonated through all the worlds.
ודו"ק כי קצרתי:
And examine this closely, for I have been brief.
He closes by signaling that he has written tersely and the reader should study the idea carefully to draw out its fullness.
Summary: The Sfas Emes explains the verse that Hashem will make Bnei Yisrael abundant in the work of their hands "for good" as a promise of the future state in which the admixture of good and evil is set right and only the good is refined out. In this world Koheles teaches that man gains no real advantage from his toil, because physical nature conceals the good and mixes waste into his every deed. But Hashem created the human being to rule over the entire world, and when a person acts straight and upright, Hashem partners in the work of his hands, granting his deeds lasting advantage. This is why the verse invokes how Hashem rejoiced over the Avos: the yetzer hara had no dominion over them, so they already tasted Olam Haba, and their every action wrought great rectifications throughout all the worlds.