A small offering lifts the whole stature

בפסוק ויקחו לי תרומה.

On the verse "And they shall take for Me a terumah (offering)" (Shemos 25:2).

The Sefas Emes opens on the command to bring contributions for the Mishkan, focusing on the word "for Me."

דכתיב אמרתי אלקים אתם ובני עליון כולכם.

For it is written, "I said, you are angelic beings (elohim), and all of you are sons of the Most High (b'nei elyon)" (Tehillim 82:6).

The posuk testifies that Bnei Yisrael were originally on an exalted, near-angelic level - all of them "sons of the Most High."

והיו מוכנים להיות כולם קדושים ושכינה שרוי' בתוכם.

And they were prepared to all be holy, with the Shechinah dwelling within them.

After receiving the Torah, every individual was poised to be holy enough that the Shechinah would rest directly within each person.

ועתה אחר החטא נתן הקב"ה עצה ע"י התרומה להיות כי הנקודה אשר קיבלו בנ"י בקבלת התורה לעולם קבוע בהם.

And now, after the cheit (of the golden calf), HaKadosh Baruch Hu gave a remedy (eitzah) through the terumah - since the [holy] point that Bnei Yisrael received at Kabbalas HaTorah is fixed within them forever.

Although the sin diminished their level, the inner point of kedushah implanted at Sinai can never be lost; the Mishkan's terumah is the means to reactivate and reveal it.

רק ההפרש כמ"ש במדרש ויקרא עליונים שיכולין לעמוד בתפקידיו של הקב"ה נאמר בהם כל מלאכיו ע"ש.

The difference is only as stated in the Midrash on Vayikra: of the supernal beings who can stand firm in the charge of HaKadosh Baruch Hu, it is said "all His angels" - see there.

The Midrash distinguishes between heavenly beings: those who fully withstand Hashem's assignment are termed "all His angels" - a complete, unwavering service.

ולכן כתיב בני עליון כולכם.

And therefore it is written, "all of you are sons of the Most High."

Before the sin, Bnei Yisrael were in that complete state - "all of you," every one, on the level of the supernal beings.

ואחר החטא אינם יכולין לעמוד בשלימות.

But after the cheit they can no longer stand firm in completeness.

The sin weakened their ability to sustain that perfect, unbroken standing before Hashem.

לכן מלאכיו ולא כל מלאכיו.

Therefore [now it is] "His angels," but not "all His angels."

Post-sin, the level is "His angels" - still holy, but no longer the absolute completeness of "all His angels."

והיינו דכתב במדרש שאמר הקב"ה קיטון א' עשה לי שעל ידי המשהו שמברר כל אחד בעצמו להיות מובדל ומופרש לשמו ית'. בזה יוכל להרים כל הקומה:

And this is what the Midrash writes, that HaKadosh Baruch Hu said, "Make Me one small chamber (kiton)" - for through the small bit (mashehu) that each person clarifies within himself, to be set apart and separated for the sake of His Name, by this he is able to lift up the entire stature (komah).

Hashem asks only for a "small chamber" - even a tiny portion that a person sets aside and dedicates entirely to Hashem. That small, sincere act of self-separation has the power to elevate the person's whole being and restore the full stature lost through sin.

Summary: Before the golden calf, Bnei Yisrael stood as "sons of the Most High," fully holy with the Shechinah within each one ("all His angels"). The sin reduced them to "His angels, but not all His angels" - yet the inner point of kedushah from Sinai remains fixed forever. The terumah for the Mishkan is Hashem's remedy: He asks only for a "small chamber," for when a person clarifies even a small bit of himself and sets it apart entirely for Hashem, that act has the power to raise his whole stature back to completeness.