The Mishkan as testimony to teshuvah

משכן העדות עדות הוא לישראל שויתר להם הקב"ה על מעשה העגל שהרי השרה שכינתו ביניהם.

"The Mishkan of Testimony" — it is a testimony for Yisrael that the Kadosh Baruch Hu forgave them for the deed of the Eigel (Golden Calf), for behold He rested His Shechinah among them.

The Mishkan is called "of Testimony" because Hashem's willingness to dwell among Bnei Yisrael proved that He had pardoned them for the sin of the Golden Calf (Rashi, from the Midrash).

ומה צריכין עדות.

But why do they need testimony?

The Sefas Emes asks: if Hashem already forgave them, what purpose does an outward "testimony" of that forgiveness serve?

אך כי נשפלו מאוד בנ"י ע"י החטא ונתן להם הקב"ה עדות ע"י המשכן לחזק את לבם ולהרחות שתיקנו כל החטא.

Rather, Bnei Yisrael had fallen very low through the sin, and the Kadosh Baruch Hu gave them testimony by means of the Mishkan to strengthen their hearts and to set them at ease that they had fully repaired the sin.

The testimony was for their own sake: after sinking so low, they needed reassurance, and the resting of the Shechinah in the Mishkan gave them confidence that the damage of the Eigel had been completely mended.

ובאמת בנ"י הם עדים על הקב"ה כדכתיב אתם עדי.

And in truth, Bnei Yisrael are themselves witnesses for the Kadosh Baruch Hu, as it is written, "You are My witnesses" (Yeshayahu 43:10).

The deeper role is reversed: Bnei Yisrael's very existence is meant to bear witness to Hashem before the world.

ובוודאי בני ישראל שנבראו להעיד על אלקותו ית"ש שהוא אחד איך יתכן שיהיו הם עובדי ע"ז ח"ו.

And surely Bnei Yisrael, who were created to testify to His Divinity, may He be blessed, that He is One — how could it be that they would be idol-worshippers, Heaven forbid?

It is inconceivable at their core that a people created precisely to proclaim Hashem's oneness should truly be idolaters; the sin could not have touched their essence.

ולכן נתרשלו בנ"י בעדותן עד שהראה להם הקב"ה שלא הי' זה החטא בעצם רק במקרה ע"י הערב רב.

Therefore Bnei Yisrael grew slack in their testimony, until the Kadosh Baruch Hu showed them that this sin was not in their essence but only incidental, through the Erev Rav (mixed multitude).

After the Eigel, Bnei Yisrael felt unworthy and faltered in their mission of bearing witness — until Hashem demonstrated, through the Mishkan, that the sin was not intrinsic to them but had come from the outside, instigated by the Erev Rav.

ושהם ראוין להעיד עליו ית"ש כבראשונה.

And that they are fit to testify to Him, may He be blessed, as at first.

The Mishkan reassured them that they remained as worthy as before to fulfill their role as Hashem's witnesses.

וכדאיתא לא היו ראוין בנ"י לאותו חטא רק להורות תשובה.

And as it is stated, "Bnei Yisrael were not fit for that sin, except to teach [the power of] teshuvah" (Avodah Zarah 4b).

Chazal teach that Bnei Yisrael by nature would never have committed such a sin; it was divinely arranged so that they could serve as a lesson in the power of teshuvah.

פי' להודיע לכל בר תשובה שלא יהי' נופל ביותר בעיניו וידע כי ע"י התשובה ניתקן כבראשונה.

That is, to make known to every penitent that he should not feel utterly fallen in his own eyes, and that he should know that through teshuvah everything is repaired as at first.

The whole episode exists to encourage every baal teshuvah: no matter how low he feels, he must realize that teshuvah can fully restore him to his original standing.

וכמו כן אחר יוה"כ שהוא יום סליחה ומחילה ניתן מצות סוכה שהיא מעין השראת השכינה במקדש לחזק לכל בעלי תשובות כי ראוים הם שתשרה שכינה עליהם:

And similarly, after Yom Kippur, which is the day of pardon and forgiveness, the mitzvah of Sukkah was given — which is like the resting of the Shechinah in the Mikdash — to strengthen all the baalei teshuvah, that they are worthy for the Shechinah to rest upon them.

The yearly pattern mirrors this: right after the atonement of Yom Kippur comes Sukkah, a form of the Shechinah dwelling with us, reassuring those who have done teshuvah that they too are fit hosts for the Divine Presence.

Summary: The "Mishkan of Testimony" reassured Bnei Yisrael, who had fallen low through the Eigel, that Hashem had fully forgiven them and that they remained worthy of their true mission — to be His witnesses to His oneness. The sin was not in their essence but came incidentally through the Erev Rav, arranged to teach the power of teshuvah; and just as the Mishkan strengthened them, so the mitzvah of Sukkah after Yom Kippur reassures every baal teshuvah that the Shechinah can once again rest upon him.