Teshuvah lifts higher than before the sin

מצות סוכה זוכין בני ישראל ע"י התשובה.

Bnei Yisrael merit the mitzvah of the sukkah by means of teshuvah.

The Sefas Emes opens by linking Sukkos to the teshuvah of the Yomim Noraim that precede it — the dwelling in the sukkah is itself a fruit of the teshuvah process.

דכ' דרכיו ראיתי וארפאהו ואנחהו.

As it is written: "I have seen his ways, and I will heal him; I will lead him" (Yeshayahu 57:18).

He reads this posuk as a map of the whole season — Hashem sees a person's ways and then heals and guides him stage by stage.

ראיתי הוא בר"ה דבאי עולם עוברים לפניו.

"I have seen" corresponds to Rosh Hashanah, when all who come into the world pass before Him in judgment.

On Rosh Hashanah Hashem "sees" every person, as all creatures file before Him like sheep before the shepherd.

וארפאהו הוא ביוהכ"פ ואנחהו הוא בחג הסוכות.

"And I will heal him" is Yom Kippur, and "I will lead him" is the festival of Sukkos.

Yom Kippur is the healing of the sin, and Sukkos is the gentle leading of the now-cleansed Yid into Hashem's protective shade.

ואשלם ניחומים הוא בשמיני עצרת תשלומין דראשון הוא.

"And I will pay him consolations" is Shemini Atzeres, which is the completion of the first day.

Shemini Atzeres is the "payment" of consolations — the final crown of the season that completes and gathers in everything that began on Rosh Hashanah.

ואמת פי' אשלם ניחומים מה שזוכין ע"י התשובה יותר מקודם החטא.

And the true meaning of "I will pay consolations" is that through teshuvah one attains even more than he had before the sin.

The "consolation" is not merely a return to the prior state but a gain beyond it — teshuvah lifts a person higher than where he stood before he fell.

כדאיתא במקום שבעלי תשובה עומדים אין צדיקים גמורים יכולין לעמוד.

As Chazal teach: in the place where baalei teshuvah stand, even complete tzaddikim cannot stand (Berachos 34b).

The one who has sinned and returned reaches a level that the perfectly righteous, who never fell, cannot reach.

והיינו לאביליו דעונות נהפכו לזכיות:

And this is "to his mourners" — that the aveiros themselves are transformed into merits.

The consolation "paid" to the mourners is the wondrous gift of teshuvah me'ahavah, where the very sins are turned into zechuyos.

Summary: The Sefas Emes maps the Tishrei season onto the posuk in Yeshayahu — Rosh Hashanah is "I have seen," Yom Kippur is "I will heal," Sukkos is "I will lead," and Shemini Atzeres is "I will pay consolations." The crowning consolation is the power of teshuvah, which lifts a person higher than before the sin and transforms his very aveiros into merits.