Two crowns, tefillin, and Shabbos lights

איתא בשעה שהקדימו ישראל נעשה לנשמע קשרו להם ב' כתרים כו'.

It is brought: at the time when Bnei Yisrael placed "na'aseh" (we will do) before "nishma" (we will hear), two crowns were bound upon them (Shabbos 88a).

The Sefas Emes begins from the well-known teaching that, in response to their declaration "we will do and we will hear," Bnei Yisrael were given two heavenly crowns.

הענין הוא בחי' התפילין של יד בחי' נעשה ושל ראש בחי' נשמע.

The matter is that the tefillin shel yad (of the hand) is the aspect of "na'aseh," and the tefillin shel rosh (of the head) is the aspect of "nishma."

The two crowns correspond to the two tefillin: the hand-tefillin embodies action ("we will do"), and the head-tefillin embodies understanding and receptivity ("we will hear").

ומה שממשיכין עתה ע"י התפילין הי' אז מורגש בנפש כל איש ישראל אותן הארות ומוחין הבאין מלמעלה.

And that which we now draw down by means of the tefillin was, back then, felt within the soul of every Jew — those illuminations and mochin (higher mental faculties) that come from above.

What we today draw to ourselves through donning tefillin was directly experienced at Sinai: every Jew tangibly felt those supernal lights and elevated states of mind.

כי כל כתר הוא המשכת כח מלמעלה מהשגת האדם והוא בחי' נשמה יתירה כמ"ש במ"א.

For every "crown" (keser) is a drawing down of a power from above what a person can grasp, and it is the aspect of a neshamah yeseirah (extra soul), as I have written elsewhere.

A crown represents an influx of strength beyond human comprehension — an added soul-light from above, the same idea as the neshamah yeseirah.

לכן בשבת אין צריכין תפילין כמ"ש חז"ל שהם עצמם אות שבשבת מחזירין לבנ"י אותן הכתרים ויכולין להרגיש מעצמם אותן ההארות שזוכין ע"י התפילין בחול:

Therefore on Shabbos one does not need tefillin, as Chazal said that [Shabbos itself] is a sign — for on Shabbos those crowns are returned to Bnei Yisrael, and they are able to feel of themselves those illuminations that on a weekday are attained by means of the tefillin.

Because Shabbos is itself an "os" (sign), the two crowns are restored to Bnei Yisrael on Shabbos, so the lights normally accessed through tefillin during the week are felt directly — making tefillin unnecessary on Shabbos.

Summary: The two crowns given for "na'aseh" before "nishma" correspond to the tefillin of the hand (action) and head (hearing); through tefillin we draw down the supernal lights and mochin that were openly felt at Sinai, but on Shabbos those very crowns are restored to Bnei Yisrael directly, so the illuminations are felt of themselves and tefillin are not needed.