Teshuvah draws purity from the upper waters

במשנה אשריכם ישראל מי מטהר אתכם אביכם שבשמים שנאמר וזרקתי עליכם מים טהורים כו' מקוה ישראל ה' כו'.

In the Mishnah (Yoma 85b): "Fortunate are you, Yisrael! Before Whom are you purified, and Who purifies you? Your Father in Heaven, as it is said, 'And I will sprinkle upon you pure waters...' (Yechezkel 36:25), and it says, 'The mikveh (hope/ritual bath) of Yisrael is Hashem...' (Yirmiyahu 17:13)."

The Sefas Emes opens from Rabbi Akiva's Mishnah, which calls Hashem Himself the One who purifies Yisrael, citing the "pure waters" of Yechezkel and "the mikveh of Yisrael is Hashem."

דכ' וזרקתי א"כ הם מים עליונים דיש מים עליונים ותחתונים כדכ' יקוו המים כו' מקום אחד.

Since it is written "And I will sprinkle," these must be supernal waters — for there are upper waters and lower waters, as it is written, "Let the waters be gathered... to one place" (Bereishis 1:9).

The word "sprinkle" (from above) indicates these are mayim elyonim, the upper waters, for creation divided the waters into upper and lower realms.

היינו שלמטה לא כל המקומות ולא כל העתים שוים.

That is, below, not all places and not all times are equal.

In the lower world of the "gathered waters," there is variation — some places and times are holier than others.

אך בנ"י שהם בחי' האחדות זוכין לתורה שנק' מים.

But Bnei Yisrael, who are the aspect of unity (achdus), merit the Torah, which is called "water."

Because Bnei Yisrael embody achdus, they are granted the Torah, itself compared to water.

אבל מים העליונים הם טהורים ושם בשורש לא שייך חטא וחסרון.

But the upper waters are pure, and there, at the root, no sin or deficiency applies.

At the level of the upper waters — the source — there is no possibility of sin or lack; it is intrinsically pure.

ולכן בעלי תשובות הקב"ה זורק עליהם ממים עליונים והיא הארת עוה"ב שמתגלה ביו"כ.

Therefore, upon ba'alei teshuvah the Holy One, Blessed is He, sprinkles from the upper waters — and this is the illumination of Olam Haba that is revealed on Yom Kippur.

Teshuvah reaches all the way to the pure source, so Hashem purifies penitents from the upper waters — a glimpse of the light of the World to Come that shines on Yom Kippur.

ובמד' ואתחנן ים רחוקים.

And in the Midrash on Va'eschanan: "the sea of distant ones."

The Sefas Emes draws on the Midrash that plays on "sea" (yam) and the far-off ones who return.

מקוה פעמים פתוחה פעמים נעולה וכמו כן התפלה.

A mikveh is sometimes open and sometimes locked, and so too tefillah.

A gathered pool of water (mikveh) may be accessible at some times and not others — and prayer is likewise: its gates open and close.

אבל שערי תשובה לעולם פתוחים ונק' ים ע"ש.

But the gates of teshuvah are always open, and it is called "yam" (sea) — see there.

Unlike prayer's intermittent gates, the gates of teshuvah never close; therefore teshuvah is likened to the vast, ever-flowing sea rather than a static mikveh.

ור"ה הוא בחי' תפלה ויוהכ"פ תשובה.

And Rosh Hashanah is the aspect of tefillah, while Yom Kippur is teshuvah.

Rosh Hashanah corresponds to prayer (gates that open and close), and Yom Kippur to teshuvah (gates ever open).

ובמד' אחרי ה' אורי בר"ה וישעי ביוהכ"פ.

And in the Midrash: "Hashem is my light" — on Rosh Hashanah; "and my salvation" — on Yom Kippur (Tehillim 27:1).

The Midrash reads "Hashem is my light" as Rosh Hashanah and "my salvation" as Yom Kippur.

כי בר"ה הקב"ה מאיר לבנ"י במקום שהם לכן היא בכסה.

For on Rosh Hashanah the Holy One, Blessed is He, illuminates Bnei Yisrael in the place where they are — therefore it is "ba'keseh" (concealed).

On Rosh Hashanah Hashem's light reaches Bnei Yisrael at their own level, within the lower world; hence it is a "hidden" illumination, "ba'keseh."

וישעי הוא ישועה מלמעלה.

"And my salvation" is a yeshuah (deliverance) from above.

Yom Kippur's "salvation," by contrast, descends from the upper realm — the pure source itself.

וכמו כן דורש שם אורי ביצ"מ וישעי על הים דשם כתיב ויושע שהי' ישועה מלמעלה כמ"ש ביום ההוא.

And likewise the Midrash there expounds "my light" as Yetzias Mitzrayim and "my salvation" as at the sea, where it is written "And [Hashem] saved (vayosha)" — for that was a salvation from above, as it says "on that day."

The same pattern maps onto the exodus ("my light") and the splitting of the sea ("my salvation"), where the Torah's word "vayosha" signals a deliverance coming entirely from above.

ולכן כ' אז ישיר.

Therefore it is written, "Then Moshe sang (az yashir)."

Because the salvation at the sea came from the supernal source, it gave rise to the complete song of "Az Yashir."

כי כשהישועה בהשורש.

For when the salvation is at the root.

When deliverance reaches all the way back to its source above.

השמחה בשלימות.

The joy is complete.

A salvation rooted in the upper source produces perfect, unblemished joy.

וכמו כן אחר יוהכ"פ הם ימי שמחה:

And likewise, after Yom Kippur the days are days of joy.

Since Yom Kippur's salvation comes from the pure root above, the days that follow — leading into Sukkos — are days of complete simchah.

Summary: From Rabbi Akiva's Mishnah, the Sefas Emes distinguishes upper waters from lower. The lower waters vary by place and time, but the upper waters are intrinsically pure, beyond sin and lack. Because teshuvah reaches all the way to that pure root, Hashem purifies ba'alei teshuvah from the upper waters — the light of Olam Haba revealed on Yom Kippur. Prayer is like a mikveh whose gates open and close (Rosh Hashanah, "my light," illumination at our own level — concealed), while teshuvah is like the ever-open sea (Yom Kippur, "my salvation," a deliverance from above). When salvation comes from the root, as at Krias Yam Suf with "Az Yashir," the joy is complete — which is why the days after Yom Kippur are days of joy.