Shabbat

[The reason is] because they  are fit for beating on an earthen utensil.  It was stated likewise: R. Jose son of R. Hanina said: [The reason is] because they are fit for beating on an earthen utensil. R. Johanan said: Because they are fit for giving a child a drink of water therein. Now, does not R. Johanan require [that it shall be fit for] a usage of its original nature?  Surely it was taught: And everything whereon he sitteth [shall be unclean];  I might think that if he [the zab] overturns a se'ah  and sits upon it, or a tarkab  and sits upon it, it is unclean: hence it is stated, 'whereon he sitteth', teaching, [only] that which is appointed for sitting, excluding this, where we say to him, 'Get up, that we may do our business!'  R. Eleazar said: In cases of midras  we say. 'Get up, that we may do our business'; but we do not say in the case of the defilement of the dead, 'Get up, that we may do our business!'  But R. Johanan maintained: In the case of defilement through the dead too we say. 'Get up, that we may do our business!'  — Reverse the former.  But what [reason] do you see to reverse the former; reverse the latter?  — Because we know R. Johanan to require [fitness for] usage of its original nature For we learnt an animal's shoe, [if] of metal, is unclean.  For what is it fit? — Rab said: It is fit for drinking water therein in battle.  R. Hanina said: It is fit for anointing oneself with oil from, it in battle.  R. Johanan said: When one is fleeing from the field of battle, he places this [shoe] on his [own] feet and runs over briars and thorns.  Wherein do Rab and R. Johanan differ? — Where it is repulsive.  R. Johanan and R. Hanina differ where it is [too] heavy. NOR WITH A GOLDEN CITY, what is meant by, WITH A GOLDEN CITY? — Rabbah b. Bar Hanah said in R. Johanan's name: A golden Jerusalem.