Bnei Yisrael complete and reveal Torah

ה' עוז לעמו יתן.

"Hashem will give strength to His people."

The Sefas Emes opens with the pasuk (Tehillim 29:11) and will read "oz" (strength) as an allusion to the Written Torah.

זה תורה שבכתב.

This refers to the Written Torah.

The "strength" Hashem gives is the Torah she-biksav.

שאף שנעלמה מעיני כל חי אעפ"כ היא עוז ועץ חיים למחזיקים בה.

For although it is hidden from the eyes of all living, nevertheless it is "strength" and an "eitz chaim" (tree of life) to those who hold fast to it.

The Written Torah's depths are concealed from every creature (cf. Iyov 28:21), yet for those who grasp it, it remains a source of strength and life (Mishlei 3:18).

ה' יברך כו' עמו בשלום היא תורה שבע"פ שהוא מצד השגת בנ"י מעצמותם כמ"ש וחיי עולם נטע בתוכנו והוא השלימות שנק' בנ"י השולמית ע"ש שהם גומרין השלימות.

"Hashem will bless… His people with peace" — this is the Oral Torah, which comes from the attainment of Bnei Yisrael through their own efforts, as it says "and eternal life He planted within us"; and this is the completeness, for Bnei Yisrael are called "the Shulamis," since they complete the perfection.

The second half of the pasuk hints at Torah she-baal peh, which Bnei Yisrael develop from within themselves — "eternal life planted within us" (from Birkas haTorah). Klal Yisrael is called "Shulamis" (Shir HaShirim 7:1), from "shleimus," because they bring the Torah to completion.

אם כי השלימות רק מהקב"ה שהוא שלומו של עולם שהשלום שלו.

Although the completeness is only from the Holy One, who is the peace of the world, for the shalom is His.

True wholeness ultimately belongs to Hashem alone, who is the very "shalom of the world" — perfection originates entirely in Him.

אבל בעוה"ז נמשך השלימות ע"י בנ"י.

But in this world the completeness is drawn down by means of Bnei Yisrael.

Even though shleimus is Hashem's, its realization within olam hazeh comes about specifically through the avodah of Bnei Yisrael.

לכן נקראו בנ"י תמכין דאורייתא שנאמר עליהם ותומכי' מאושר שהם הרגלים והיסוד שהתורה תהיה נגלית בעוה"ז על ידיהם כנ"ל:

Therefore Bnei Yisrael are called the "supporters of the Torah" (tamchin d'Oraisa), of whom it is said, "and those who support it are fortunate," for they are the "legs" and the foundation through which the Torah becomes revealed in this world, as above.

Bnei Yisrael are the "supporters of Torah" (cf. Zohar) — "those who uphold it are praiseworthy" (Mishlei 3:18) — serving as the foundation through which the Torah is made manifest in this world.

Summary: "Hashem gives strength to His people" alludes to the Written Torah, hidden yet an eitz chaim for those who hold it, while "He blesses His people with peace" alludes to the Oral Torah, which Bnei Yisrael complete from within. Though all shleimus belongs to Hashem, it is drawn into this world through Bnei Yisrael, the "supporters of Torah" who serve as the foundation for its revelation.