“…And he made the copper washbasin and its copper base from the mirrors of the legions of women…” – Shemos 38:8

וַיַּעַשׂ אֵת הַכִּיּוֹר נְחשֶׁת וְאֵת כַּנּוֹ נְחשֶׁת בְּמַרְאֹת הַצֹּבְאֹת – שמות לח, ח

The Talmud (Yevamos 49b) contrasts Moshe with all the other prophets: “All the prophets looked into a dim glass, but Moshe looked through an illuminated glass.” Moshe’s prophecy and perception of the Divine was comparable to one looking through “an illuminated glass”—a telescope, which enables you to see distances unseen by the naked eye. In contrast, the other prophets’ perception of the Divine was through a “dim glass”—a coated glass that expands your range of view to include angles that are not directly visible, i.e. a mirror. Both of these instruments bring the unseen into view, but whereas through a telescope one sees the distant objects themselves, through a mirror one sees only reflections. Analogously, the other prophets saw only a reflection of the Divine, but Moshe was given a glimpse of the Divine Itself (see Torah Ohr 33a).

This explains the Midrashic account that the personal mirrors brought by the women as a contribution to the Mishkan were repulsed by Moshe, who viewed these mirrors as instruments of lust and temptation. G-d told Moshe to accept them nonetheless, saying, “These are more precious to Me than all else because through them the women produced the legions (they gave birth to) in Egypt.”

The women’s mirrors epitomized perceiving G-d through His reflection and shadows—discovering that even what seems at odds with holiness can also reflect the Divine. In this instance, instruments of selfish lust were “redirected” toward a G-dly purpose by the Jewish women in Egypt, who used these mirrors to facilitate the birth of a generation of Jews in the direst of times. But Moshe anticipated the construction of the Mishkan—a dwelling place for G-d, as an opportunity for G-dliness to be revealed openly and directly, as he was accustomed to in prophecy. Why blur this revelation by incorporating in the Mishkan the aspects of life in which G-d is only indirectly manifest?

But G-d told Moshe to accept the mirrors. For the discovery and revelation of G-d’s reflection even in the areas where He is normally “out of sight” is the ultimate fulfillment of His desire to dwell and be manifest in the lowest elements of this world. Though the G-dly revelation therein is only indirect, but the Divine pleasure that this challenge elicits is “more precious to Me than all else.”

—Likkutei Sichos vol. 6, pp. 197-199