Tuesday, February 15, 2022

Adar paradox

The gemara (Archin 31b) has the following din:

וא"ר אבא בר ממל נולדו לו שני טלאים אחד בחמשה עשר של אדר הראשון ואחד באחד באדר השני זה שנולד ה] באדר השני כיון שהגיע יום אחד באדר (השני) של שנה הבאה עלתה לו שנה זה שנולד לו בחמשה עשר באדר הראשון לא עלתה לו שנה עד חמשה עשר באדר של שנה הבאה

A farmer has 2 lambs that are bechorim, one born 15 Adar I, one born on 1 Adar II.  The halacha is each must be offered as a korban within their first year.  If the next year is a non-leap year, the second lamb that was born on 1 Adar II will reach its one year deadline on 1 Adar.  The lamb born first on 15 Adar 1 will reach its deadline second, on 15 Adar.

Applying the same logic to bar mitzvah boys, in a non-leap year a boy born on 15 Adar I will become bar mitzvah two weeks after a baby born on 1 Adar II, even though he was born first.  

The Shvus Yaakov (#9) raises the following paradoxical question: there are halachos that apply to the elder or eldest child in a family, e.g. there is a din that the eldest child takes precedence to do the mitzvah of yibum, there is a din of kavod that applies to older brothers.  

When it comes to these two brothers, who is the eldest?   (You can have brothers born 2 weeks apart from different mothers, assuming you like in a place where cheirem d'Rabeinu Gershom never took hold.)  Is it the brother than was born first, or is it the brother that becomes bar mitzvah first?  Is it possible to have a bar mitzvah, blow out all 13 candles in one's birthday cake, and still be considered the halachic younger brother of someone whose bar mitzvah is only 2 weeks later?


  1. Why would the Bar Mitzvah date have anything to do with it? The two halachos you cite are for the "gadol," which would mean who was born first.

    If we were talking about who is the bechor (of the father, for yerusha) I think it is clear that the first-born gets it.

    1. >>>Why would the Bar Mitzvah date have anything to do with it?

      Because normally if person A celebrates their birthday before person B, it means person A is older than person B. So you have to say a bar mitzvah is not a birthday, but rather something else... but what?

    2. Min ha Torah, to reach adulthood, you need shanim v'simanim.* So let's say that one brother is delayed a bit, and the other one reaches shanim v'simanim first. Does that mean he is now the ach ha gadol, even though the other one was born first. Don't think so.

      * This is still the halakha for deoraysas. These include, being qualified to do a chalitza, making kiddush Friday night, and leining parshas Zachor. I once was at a Bar Mitzvah on parshas Zachor, and while the bar mitzvah boy leined, Zachor was leined by someone else who had a beard and was clearly a gadol.

  2. The bar mitzvah is a change in status vis a vis legal responsibilities. The boy who was first out established that status when he was born.