Erchin 18b.
Tosafot DH "UFDUYAV" suggests that "MIBEN CHODESH", as opposed to "BEN CHODESH", without "MI" (written in relation to the bechor), mashma MIBEN CHODESH VAMALA (more than 30 days, but not 30 days). Similarly, the KESEF MISHNEH in Erchin vecharamin 1.3, when trying to understand from where we know that YOM SHELOSHIM KELEMATA MIMENU, in the last explanation, states that VEIM MIBEN CHODESH MASHMA CHODESH SHALEM, BEN CHODESH VEYOM ECHAD. My question is (for the tosafot and the kesef Mishneh) if MIBEN CHODESH mashma MORE than 30 days, why then we need the gezera shava SHANAH SHANAH from 60 years to learn that also exactly 20 and 5 years is kelemata mimenu? (note that in 20 and 5 years the Tora also says MIBEN CHAMESH SHANIM, MIBEN ESRIM SHANAH). Thanks!!
Shalom Reb Dino,
It is a pleasure to hear from you, and thank you for your thoughtful and perceptive question.
At first glance, one might resolve the issue by distinguishing between two types of contexts:
1. Fixed thresholds, such as Pidyon ha'Ben, where the Torah sets a clear minimum age ("from one month and onward"). In this case, as Tosfos explains, it would have been sufficient to write "Ben Chodesh." The use of "mi'Ben" therefore appears superfluous, providing room for a Derashah.
2. Age ranges , such as those in Erchin (five until twenty, twenty until sixty, etc.). Here, the use of "mi'Ben" is more natural, since the Torah must mark both the lower and upper boundaries of the range. In such a context, the "Mem" is arguably not superfluous, and therefore less available for Derashah. This distinction might explain why Tosfos interprets "mi'Ben" differently in Pidyon ha'Ben, while for Erchin we require the Gezeirah Shavah from sixty.
However, several sources suggest that the true picture may be more nuanced. For example, Bechoros 49a teaches that the source for Pidyon ha'Ben being at 31 days -- i.e. that 30 days is still considered "l'Matah" -- is derived from the census of the Leviyim, (where the Torah writes "Ma'alah," indicating that 31 is the threshold). This contrasts with Tosfos' approach, which learns the same conclusion from the extra "Mem" in "mi'Ben." (See Panim Me'iros 1:3 and Tosfos Chadashim to Mishnayos, end of Perek 4.)
Additionally, let's turn to the Kesef Mishneh who offered two answers to his question (how do the Chachamim who disagree with Eliezer know that thirty days is considered "l'Matah" in Erchin?): 1) Even without accepting the Gezeirah Shavah, the Chachamim agree that there is a Giluy Milsa (either from the Leviyim according to Rashi, or from Pidyon ha'Ben according to Tosfos); 2) In the case of Erchin, the Torah indeed says "mi'Ben" rather than simply "Ben," from which we can infer the point.
It is important to realize that some raise a difficulty on this Kesef Mishneh, for they argue that the rule of "thirty days is l'Matah" in Erchin is not derived from "mi'Ben" but rather from the analogy to the other age categories in Erchin (5, 20, 60). See the Rashash (Bechoros 49a, DH mid'Itzterich) who explains this based on Rashi (ad loc., DH Misapka).
May you continue to grow in Torah and Yir'as Shamayim.
Warmly,
Yishai Rasowsky
Shalom Reb Dino,
It is wonderful to hear your response. Yes, I think you are right about all these points. I appreciate your explaining them so clearly. I had not thought of them before.
May you continue to attain greatness in Torah and Yir'as Shamayim!
Warmly,
Yishai Rasowsky