[Avodah] The Scope of the "7 Mitzvos d'Rabbanan"

[Daniel Eidensohn]

The Ramban has similar concerns about the significance of saying there 
are 613 mitzvos. He discusses it a length in his comments to Shoresh I 
of the Rambam's Sefer HaMitzvos

R Micha Berger wrote:
> I never understood the import of R Simla'i's words about the original
> 613, never mind the additional 7 derabbanan. Here we have a maamar from
> a single tanna that we can group the thousands -- millions? potentially
> infinite? -- dinim deOraisa into 613 mitzvos. And based on this we have
> an entire genre of seifer in which geonim and rishonim figure out
> systematic ways to do so.
>