The Torah in Parashat Vayakhel (38:8) tells that the kiyor, the water basin from which the kohanim washed their hands before entering the Mishkan, was made from mirrors donated towards the Mishkan by the women among Benei Yisrael. Rashi, citing the Midrash Tanchuma, famously comments that Moshe was initially ambivalent about using mirrors, articles used for cosmetic purposes, as part of the Mishkan, but God instructed him to include this donation. These mirrors, the Midrash explains, were used by the women in Egypt to adorn themselves and thereby entice their husbands to intimacy. The men would return home from their day of crushing labor physically and emotionally shattered, and the wives are credited with lifting the men’s spirits and ensuring the continued growth of Benei Yisrael’s population. God therefore told Moshe that He regarded these mirrors as the most precious of all the materials donated toward the construction of the Mishkan.
Rav Dov Weinberger, in his Shemen Ha-tov, explains this Midrashic passage in light of the comments of the Da’at Zekeinim Mi-Ba’alei Ha-Tosafot earlier (35:27), describing the women’s special enthusiasm for the Mishkan. The Da’at Zekeinim cites the Midrash’s criticism of the men among Benei Yisrael, all of whom happily donated their gold towards the golden calf, but only some of whom parted with their wealth for the purpose of constructing the Mishkan. By contrast, the women refused to allow their husbands to donate their jewelry towards the golden calf, but responded with enthusiastic generosity to the call for materials for the Mishkan, rushing eagerly to bring their jewelry. Rav Weinberger suggests that this description of the women closely relates to the Midrash’s account of their efforts to encourage their husbands in Egypt. Just as the men felt despair during the period of bondage in Egypt, similarly, they felt discouraged and helpless after the grave incident of eigel ha-zahav (the golden calf). It was difficult for them to imagine that God agreed to forgive their misdeed and have His Shekhina reside among them. Once again, it was the women who remained upbeat and optimistic, confident in God’s compassion and love for His people. Just as the wives lifted their husbands’ spirits as they suffered physical torment in Egypt, they likewise succeeded in lifting their husbands spirits in the aftermath of the spiritual failure of cheit ha-eigel.
On this basis, Rav Weinberger suggests a possible explanation for the famous tradition, noted by the Da’at Zekeinim, that in reward for abstaining from the golden calf, the women were given a holiday, of sorts, each Rosh Chodesh. It was customary in some communities for women to refrain from work on Rosh Chodesh, and this holiday was seen as a reward for the women’s refusal to take part in the golden calf. The monthly occasion of Rosh Chodesh, when the moon is at its smallest point and then begins to grow anew, symbolizes hope and optimism, the prospect of growth and recovery after a period of decline. Just as it seems as though the moon would disappear, it begins to enlarge, a process which alludes to the possibility of renewal and rebirth even in situations that seem hopeless. Appropriately, this occasion is associated with the courageous optimism displayed by the women among Benei Yisrael, who remained positive, hopeful and optimistic even during the nation’s darkest moments – during the period of physical suffering in Egypt, and in the aftermath of the golden calf.