In his question on Rashi's pshat on which R'G is making the gezeira on shechita by kusim after the gezeira of R'M regarding stam yenam, Tosfos is perplexed that if R'M made a gezeira regarding all kusim for stam yenam, a d'rabbonon - why wouldn't R'M make a gezeira as well regarding shechita by a kusi which is d'oraisa? What does it mean exactly that shechita is d'oraisa? Clearly the issur of a kusi by shechita cannot be d'oraisa because a kusi was - until then - allowed to shecht (although with someone watching him). So, what's the d'oraisa?
Thanks,
D, Clifton, NJ
Tosfos means that the prohibition against eating an animal without any shechita at all is d'oraisa. Therefore if someone who is certainly not a Yisrael slaughtered an animal this is forbidden medeoraisa. In contrast if someone who is certainly not a Yid touched the wine this is only forbidden miderabonon. The intention of Tosfos is that if R'M made a gezera in an area of Halacha which can at the most only be a Rabbinical issur, then he should certainly make a gezera concerning shechita which can potentially involve a Torah prohibiton if it is done in a totally wrong way.
In short when Tosfos writes that shechita is deoraisa he does not mean specifically the shechita of a kusi, since up to now this has been permitted as you write, but rather he means that shechita in general is a Torah prohibition, whilst in contrast non-Kosher wine in general is only a rabbinical prohibition.
KOL TUV
Dovid Bloom