Shalom as the vessel for blessing

בברכת כהנים כה תברכו את בני ישראל.

Regarding Birkas Kohanim: "Thus shall you bless Bnei Yisrael" (Bamidbar 6:23).

The Sefas Emes begins from the mitzvah of the kohanim's blessing of the people.

פי' שבנ"י הם כלים להמשיך הברכה על ידיהם כדכתיב ושמו את שמי כו'.

The meaning is that Bnei Yisrael are vessels through whom the blessing is drawn down, as it is written, "and they shall place My Name [upon Bnei Yisrael, and I will bless them]."

Klal Yisrael serve as the keilim (vessels) that receive and channel Hashem's blessing — the kohanim place Hashem's Name upon them, and Hashem Himself bestows the berachah.

דאיתא אין כלי מחזיק ברכה אלא שלום.

For it is stated: "No vessel holds blessing except shalom (peace)."

Chazal teach that the only "vessel" capable of containing and retaining blessing is peace — wholeness and harmony.

והשלימות אינו בנמצא רק בבנ"י שנקראו השולמית ובמד' אומה שמסיימים לה שלום בכל יום.

And completeness (shleimus) is found only in Bnei Yisrael, who are called "the Shulamis," and in the Midrash, "a nation for whom they conclude with peace every day."

True wholeness exists only in Klal Yisrael — called "Shulamis" (from shalom/shaleim) in Shir HaShirim — the nation whose daily prayers and Birkas Kohanim conclude with "shalom."

ולכן הם יכולים לקבל הברכה והקב"ה נותן ברכתו תמיד מן השמים כשיש כלי לקבל.

Therefore they are able to receive the blessing, and the Holy One, blessed is He, gives His blessing constantly from heaven whenever there is a vessel to receive it.

Because Yisrael possess shalom, they form the vessel for blessing; Hashem's berachah flows down ceaselessly, needing only a fit vessel to hold it.

וכמו כן בביהמ"ק דכתיב בכל המקום אשר אזכיר את שמי כו'.

And likewise regarding the Bais Hamikdash, as it is written, "in every place where I cause My Name to be mentioned [I will come to you and bless you]" (Shemos 20:21).

The same principle of a vessel for blessing applies to place — the Bais Hamikdash, where Hashem's Name rests and blessing descends.

ולא כתיב בכל מקום אלא המקום.

And it does not write "in every place" but "the place."

The Sefas Emes notes the verse's precise wording: not just "anywhere," but "ha-makom" — the defined, all-encompassing place.

היינו מקום שכולל כל המקומות והוא ביהמ"ק.

That is, a place that includes all places — namely, the Bais Hamikdash.

"Ha-makom" denotes the one place that gathers all places into itself: the Mikdash, the focal point of space.

וכמו כן יש זמנים שכולל כל הזמנים.

And likewise there is a time that includes all times.

Just as there is a comprehensive place, so there is a comprehensive time — Shabbos — that gathers all times into itself.

וזהו השלימות שנמצא בעולם שנה נפש ושורה ע"ז הברכה כנ"ל.

And this is the completeness found in olam, shanah, nefesh (space, time, soul), upon which the blessing rests, as explained above.

In each of the three axes there is a point of shleimus — the Mikdash in space, Shabbos in time, Yisrael in soul — and on this completeness Hashem's blessing settles.

ועיקר פירוש שלום כתבנו במ"א כי חלק שלמטה הוא פלג גופא רק בנ"י יש להם דביקות בחלק העליון ונק' שלום.

And the main explanation of "shalom" we wrote elsewhere: that the lower portion is "half a body," but Bnei Yisrael have attachment to the upper portion, and [thus] are called "shalom (whole)."

Whatever exists only in this lower world is but "half a body," incomplete. Bnei Yisrael, through their deveikus binding them to the supernal upper portion, become whole — and that wholeness is called shalom.

וכמו כן בהמ"ק דכתיב כעיר שחוברה לה יחדיו ונק' שלם.

And likewise the Bais Hamikdash, of which it is written, "like a city that is joined together," and is called "Shalem (Yerushalayim)."

Yerushalayim, "the city joined together," unites the earthly city with its heavenly counterpart — hence it is called Shalem, whole, mirroring the same wholeness of upper and lower joined.

וזה הרמז נשיאות כפים כמ"ש שאו ידיכם קודש.

And this is the allusion in the raising of the hands (nesias kapayim), as it is written, "Lift up your hands [in] holiness" (Tehillim 134:2).

The kohanim's raising of their hands in Birkas Kohanim hints at this joining of lower to upper, alluded to by "lift up your hands in kodesh."

יד הוא מקום כמ"ש בזוה"ק בהיכלות דפקודי בענין נטה ידך ע"ש.

"Yad (hand)" denotes a "place," as stated in the Zohar HaKadosh, in the Heichalos of [parshas] Pekudei, concerning "stretch out your hand"; see there.

Drawing on the Zohar, the Sefas Emes notes that "hand" can signify a place or domain — so raising the hands signifies elevating and connecting the realms.

וידיכם קודש הוא היד והכח שיש להם בקדושה והכהן מדביק חלק שלמטה בחלק של מעלה.

"Your hands [in] holiness" is the "hand" and the power that they have in kedushah; and the kohen attaches the lower portion to the upper portion.

The kohen's raised hands represent his power in holiness to bind the lower realm to the upper — joining heaven and earth and thereby drawing down blessing.

וכ' וישא אהרן כו' ידיו.

And it is written, "And Aharon lifted up… his hands [toward the people and blessed them]" (Vayikra 9:22).

The Torah records Aharon raising his hands to bless the nation, the prototype of Birkas Kohanim.

הוא הכח של הכהן והוא בחי' החסד שניתן לאברהם אע"ה.

This is the power of the kohen, and it is the aspect of chesed that was given to Avraham Avinu.

The kohen's blessing-power flows from the middah of chesed — the attribute embodied by Avraham, from whom Aharon and the kohanim draw this capacity.

וזה הכח נמסר להכהן לברך את ישראל באהבה.

And this power was transmitted to the kohen to bless Yisrael with love.

The chesed of Avraham was handed down to the kohanim, who therefore bless Yisrael "be-ahavah," with love.

ורמזו במדרש בענין והיה ברכה ע"ש:

And they alluded to this in the Midrash regarding "and you shall be a blessing" (Bereishis 12:2); see there.

The Midrash on Hashem's words to Avraham, "and you shall be a blessing" — that the power of blessing was placed in his hands — is the source the Sefas Emes points to for the kohanim inheriting Avraham's chesed and capacity to bless.

Summary: Birkas Kohanim works because Bnei Yisrael are the vessel for Hashem's blessing, and the only vessel that holds blessing is shalom — wholeness, which comes from Yisrael's deveikus binding the lower realm to the upper. This wholeness has its focal point in each of the three axes: the Mikdash ("the place"/Shalem) in space, Shabbos in time, and Yisrael in soul. The kohanim's raised hands join lower to upper, drawing on the chesed of Avraham to bless Yisrael with love.