Mishnayos Oholos Perek 5 Mishnah 5

כלי גללים – of excrement of cattle.

כלי אבנים וכלי אדמה – al of these are vessels, even in the hand of illiterate people they are pure, and if they are placed upon the aperture in the roof looking to the ground fall, it protects over everything even on the vessels which require only rinsing to be restored to Levitical cleanness.

היה כלי טהור לקודש ולחטאת – for the Rabbis appointed them to the illiterate people on the Holy Things, in order that each person would not go and build an altar for himself, therefore, the vessel that is pure for Holy Things protects on everything, even according to the School of Shammai, and similarly, they are deemed faithful on the sin-offering of the ashes of the Red Heifer, as it is written (Numbers 19:9): “[A man who is pure shall gather up the ashes of the cow and deposit them outside the camp in a pure place,] to be kept [for water of lustration] for the Israelite community,” everyone is believed on its preservation.

מפני שהכלים טהורים – as for example, vessels of excrement and vessels of stones and vessels of earth which are pure from being susceptible to receive impurity. And similarly, earthenware vessels are pure when they are for Holy Things and for purification [water]. Even though they belong to an illiterate person, he is believed, for an illiterate person is believed for Holy Things and for purification [water] as we have stated.

כל אלו מצילין עם דפנות אוהלים – that is to say, they interpose in the face of defilement when they are placed in a place where there are walls of tents, and this aperture in the roof looking to the ground floor that is between the house and the upper chamber is considered like the walls of tents. But in a place where there are no walls, it does not protect, as will be explained further on (see the next Mishnah).