The physical and metaphyical
Recently, I commented on a misinterpretation of the saying of Chazal recorded on p. 31 of Tractate Niddah isha mazria techila yoledes zachar. The conception of a boy is attributed to the female in this case. While some like to point to this as "proof" that Chazal were ch"v wrong about biological function, in truth Chazal's understanding of conception encompasses the biological and the metaphyscial.
See p. 23 of Eyt Dodim the paperbound supplement to Rav Elyashiv Knohl's Ish V'Isha reviewed here. The gist of it is that the mazria does not refer to ovulation, but to the si-- to use the Hebrew term. (Hamevin yavin, as we say.) As it says in other parts of the same page of that Talmud, this is offered as advice to men who wish to have sons. Rabbi Knohl explains, Chazal were not offering this as a biological fact but as a "amira musarit" for the man who would be concerned about his wife and not just himself will merit that the Holy One Blessed be He will consider the man's desires and grant him a son, which appears in many places as the example of the prime desire of man. R' Knohl offers as proof of his point that Niddah 71 says, Mai schar pri habeten? ... Bischar shemashhin atzman babeten kedey shetazria ishto techila nothen lo Hakadosh Barush Hu schar pri habeten. So it is explicit that this is a schar - a reward - from Hasham, and not a law of nature.
On to the philosophical point that the Meshech Chachma makes on Parshas Kedoshim: Bizman sheisha mazras techila yoledet zachar (Nidda 31a) vezeh "shiru laHashem shir chadash" (Yeshayahu 42:10) shir zachar, vehadvarim amukim. When a woman give forth first, she gives birth to a male child, and this refers to the verse, "Sing to G-d a new song." The word for song here is masculine, and the matter is a deep one. Rabbi Copperman's edition offers this footnote: the intentions her is to teach that when the actions begins from below (as connoted by female) it will render the completion from the source of holiness above (the male).
The mater is a deep one, which touches on a number of points about spiritual redemption. The feminine form, shira is what we experienced in the redemption from Egypt, and in the future, we will have a stronger form of redemption, which is connoted in the masculine form of shir. The difference is that when the female, which represents the Jewish people, will act first -- awakening from below -- then the completion will come from above in a stronger form than when the first move has to come from above to stir the Jewish people into a response.
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