[Avodah] Kos Shel Beracha

[Lawrence Teitelman]

R' Akiva Miller:
<< As far as I can imagine, there is no mitzva which -- on a D'Oraisa 
level -- requires us to say certain words over a cup of wine. Wine is 
used in certain korbanos, but so is water, grain, fruit, fowl, and 
many other items. The idea of linking a speech to a kos seems new to 
me. <SNIP> What do others think? Am I totally off base, or what? >>

MYG:
<<As per a shiur I heard tonight on our local radio station, Tosfos (Pesachim
106a, s.v. Zochreihu, at the end) hold that it's D'oyraisa. Apparently
Tosfos in other places says this as well, but this was the only Mareh Makom I caught.>>

See also Nazir 4, Rashi d"h Veharei and Tos. d"h Mai Hi.