There (in Bavel) they say that the 24 hours that they said, her Mishkav is like what she touches;

Suggestion: What [is the law of her Mishkav]? Is it like [that of] a Bo'el Nidah, and it is not Metamei a Kli (only food and drink)!

Rejection (Beraisa): [24 hours of Nidah] is Metamei a Kli Cheres [surrounded with a Tzamid Pasi] through Heset (if she moved it, like a Nidah. Rather, we must say that her Mishkav is Metamei one who sits on it like someone she touches; he is Metamei Begadim.)

Question: The 24 hours that they said - what is the law of what she touched in Reshus ha'Rabim? (Normally, Safek Tum'ah in Reshus ha'Rabim is Tahor.)

Answer: We learn from the following [Tosefta]. A pregnant or nursing woman is Tehorah to her husband (she need not check herself), and similarly, a woman who has a Veses. All other women are Tahor through Bi'ah (retroactively) and Metamei through touching;

Inference: [The Tosefta said Stam that she is Metamei through touching, i.e. ] what she Vadai touched [even] in Reshus ha'Rabim is Tamei.