[Avodah] bat mitzva "bo bayom"

[Zev Sero]

Micha Berger wrote:

> However, we discussed this already recently WRT geir qatan and the time
> for QOM (or whatever it is he is doing). DeOraisa, all you need is 2
> sa'aros. We require waiting for the child's age in order to be sure
> they're really pubic, and not a mole or some other random hair. (And for
> deRabbanan we wait for the age instead of bothering to check
> altogether.) IOW, it's not when they are chayavos deOraisa, it's when we
> know they're chayavos. E.g. WRT zimun (assuming you're not a Sepharadi
> who will count for zimun any child who can understand what benching is;
> Rambam, Rif).
> 
> The halakhah deOraisa has no significance to a particular age, and is
> entirely about the individual's rates of development.

I'm sorry, what is your source for this?  AFAIK shanim are absolutely
required, and any hair before the appropriate age *is* shuma.  We're
not "unsure" whether it's shuma, it's shuma by definition.


-- 
Zev Sero               Something has gone seriously awry with this Court's
zev at sero.name          interpretation of the Constitution.
                       	                          - Clarence Thomas