Shabbat

Now according to Hananiah, carrying by means of oxen is regarded as carrying.  For we learnt: There are three waggons: That which is built like a cathedra  is liable to uncleanness as midras;  that which is like a bed  is liable to uncleanness through the defilement caused by a corpse;  that of stones  is completely clean. Now R. Johanan observed thereon: But if it has a receptacle for pomegranates, it is liable to uncleanness through the defilement of a corpse.  There are three chests: a chest with an opening at the side is liable to uncleanness as midras;  at the top, is liable to uncleanness through the defilement of a corpse;  but an extremely large one  is completely clean. Our Rabbis taught: The midras of an earthen vessel is clean;  R. Jose said: A ship too. What does he mean?  — Said R. Zebid. He means this: The midras of an earthen vessel is clean, but contact there with renders it unclean,  while an earthen ship is unclean, in accordance with Hananiah;  R. Jose ruled: An [earthen] ship too is clean, in agreement with our Tanna. R. Papa demurred: [if so,] why say, A ship too?  Rather said R. Papa, This is its meaning: The midras of an earthen vessel is clean, whilst contact therewith defiles it; but [in the case of a vessel] of wood, both its midras and its touch are unclean; while a boat of the Jordan is clean, in agreement with our Tanna; R. Jose said: A ship too is unclean, in accordance with Hananiah. Now, how do we know that the midras of an earthen vessel is clean? — Said Hezekiah, Because Scripture saith, and whosoever toucheth his bed.  this assimilates 'his bed' to himself [the zab]: just as he can be cleansed in a mikweh,  so can 'his bed' be cleansed in a mikweh. The School of R. Ishmael taught: It shall be unto her as the bed of her impurity [niddah]:  this assimilates her bed to herself: just as she can be cleansed in a mikweh, so can 'her bed' be cleansed in a mikweh, thus excluding earthen vessels, which cannot be cleansed in a mikweh.  R. Ela raised an objection: How do we know that a [reed] mat [is susceptible to defilement] through the dead?