Yom Kippur forgiveness rekindles the desert merit

יום הכפורים יום סליחה ומחילה בכלל ובפרט ויש בו סליחות חטא העגל כמ"ש ז"ל בפסוק וביום פקדי ופקדתי שאין פקודה שאין בו מחטא העגל והטעם לפי שעי"ז נסבבו אח"כ כל החטאים.

Yom Kippur is a day of forgiveness and pardon, both in general and in particular, and it contains the forgiveness for the sin of the Golden Calf — as Chazal say on the verse "and on the day that I make My accounting, I shall bring their sin to account" (Shemos 32:34): that there is no reckoning that does not contain some portion of the sin of the Calf — the reason being that through it all later sins were brought about.

The cheit ha'egel (sin of the Golden Calf) is the root from which every later sin draws, so every accounting carries a trace of it; thus Yom Kippur's forgiveness reaches back to atone for that primal sin.

וכמו כן מדה טובה מרובה שאין סליחה שאין בו סליחות העגל דגם כל התשובות שבנ"י עושין תמיד וכל הסליחות הכל בכח התשובה והסליחה של דור המדבר כמ"ש חז"ל שלא היו ראוין לאותו החטא רק כדי להורות תשובה.

And likewise — since the measure of good is greater — there is no forgiveness that does not contain the forgiveness of the Calf, for all the teshuvos that Bnei Yisrael ever do and all the pardons are entirely by the power of the teshuvah and the forgiveness of the dor hamidbar (the desert generation), as Chazal say that they were not really fit to commit that sin, but only in order to teach the way of teshuvah.

Just as the Calf is the root of sin, its forgiveness is the root of all forgiveness; the desert generation sinned only to model teshuvah for all future generations, so every later act of teshuvah draws on their original repentance.

לכן כל זמן שבנ"י עושין תשובה מתעורר זכות דור המדבר.

Therefore, whenever Bnei Yisrael do teshuvah, the merit of the desert generation is awakened.

Every act of teshuvah reactivates the zechus (merit) of the dor hamidbar, who first opened the gateway of repentance.

ובכל שנה נמחק קצת מן החטא עד לעתיד שיהי' מתוקן כל החטא ויזכו בנ"י למה שהיו ראוין להיות קודם החטא כמ"ש אמרתי אלקים אתם.

And each year a portion of the sin is erased, until in the future the entire sin will be rectified and Bnei Yisrael will attain what they were fit to be before the sin, as it is written, "I said, you are angelic beings" (Tehillim 82:6).

The cheit ha'egel is being cleansed bit by bit each year, until the geulah, when it is fully rectified and Bnei Yisrael return to the exalted, angelic level they held before the sin.

ולכן ביוה"כ דומין למלאכים והוא אות שעתידין להיות קדושים.

Therefore, on Yom Kippur we resemble the angels, and this is a sign that we are destined to become holy.

On Yom Kippur Bnei Yisrael are angel-like — fasting and free of sin — a foretaste and sign of the future state of complete kedushah.

ובני ישראל מתענין בשמחה לומר שמצפים לחזור למדריגה זו הראשונה שלא נצטרך לאכילה ושתי' רק להיות ניזונים מזיו השכינה כמלאכים:

And Bnei Yisrael fast with joy, to declare that they look forward to returning to that original level, where we will not need food and drink but will be nourished from the radiance of the Shechinah, like the angels.

The joyful fasting expresses yearning to return to the pristine pre-sin level, where Bnei Yisrael will be sustained directly by the glow of the Shechinah rather than by physical food.

ולפי שע"י הסליחה נזכר שבחן של דור המדבר לכן מצות סוכות אחר יוהכ"פ כמ"ש זכרתי לך חסד נעוריך זכות דור המדבר.

And since through the forgiveness the praise of the desert generation is recalled, therefore the mitzvah of Sukkos comes right after Yom Kippur, as it is written, "I remember for you the kindness of your youth" (Yirmiyahu 2:2) — the merit of the desert generation.

Once Yom Kippur's forgiveness has reawakened the merit of the dor hamidbar, Sukkos follows immediately to celebrate that very merit — the loving devotion of Bnei Yisrael's "youth" in the wilderness.

כי ע"י החטא נכבה הזכות וע"י התשובה חוזר ומתעורר הזכות.

For through the sin the merit was extinguished, and through the teshuvah the merit is rekindled and reawakened.

Sin dims the underlying zechus of Bnei Yisrael, but teshuvah relights it, restoring the merit of the desert generation.

כמ"ש הר"י ז"ל בשערי תשובה בפסוק תשא עון וקח טוב ע"ש:

As Rabbeinu Yonah writes in Shaarei Teshuvah on the verse "forgive iniquity and accept good" (Hoshea 14:3) — see there.

The Sefas Emes points to Rabbeinu Yonah's teaching that teshuvah not only removes sin but transforms it into merit, supporting the idea that repentance rekindles the dormant zechus.

Summary: Yom Kippur's forgiveness reaches the root of all sin — the cheit ha'egel — and its pardon is the root of all pardon, for the desert generation sinned only to teach the way of teshuvah, so every later repentance draws on their merit. Each year a portion of that sin is erased, until the future when Bnei Yisrael will return to their pre-sin, angelic level, nourished by the radiance of the Shechinah; this is foreshadowed by the angel-like, joyful fasting of Yom Kippur. Because forgiveness reawakens the merit of the desert generation, Sukkos — celebrating the "kindness of your youth" — follows immediately, for teshuvah rekindles the merit that sin had extinguished.