[Regarding] a sheretz that was found beneath the floor of an oven, [the oven is] tahor, for I say: It fell while alive and [only] now did it die. [Regarding] a needle or ring that was found beneath the floor of an oven, [the oven is] tahor, for I say: They were there before the oven arrived. [If] they were found in the ashes, [the oven is] tamei, for there is nothing to which it can be attributed.