Parah, Chapter 5, Mishnah 5. This chapter is occupied with the vessels used in preparing the chatas water: the vessel in which the spring water is drawn, and the vessel in which the ashes of the parah adumah are placed into that water, the act called kiddush, sanctifying the water. Our mishnah teaches which kinds of vessels are acceptable for this, and, just as importantly, what does not qualify as a vessel at all.
Every Kind of Vessel Is Acceptable
The mishnah opens with a sweeping permission: "Bechol hakeilim mekaddeshin" - the kiddush may be carried out in any vessel at all. It then spells out examples one might have doubted, "afilu bichli gelalim", even a utensil formed from dried cattle dung, and likewise "bichli avanim", one hewn out of stone, and "uvichli adamah", one shaped from earth that was never fired. Why name precisely these three? Because they are not the materials people normally use for household utensils, so a reader might have assumed they are unfit; the mishnah teaches that for this purpose they serve fully. One more case is added: "Uvisfinah mekaddeshin bah" - the water may even be sanctified inside a boat.
What Is Not a Vessel
Having shown how broad the allowance is, the mishnah now marks the boundary. "Ein mekaddeshin", the sanctifying may not be performed "bedofnos hakeilim", in the detached side pieces of broken utensils, nor "bishulei hamachatz", in the lower portion of a scooping ladle, nor "bimgufas hachavis", in the plug that seals a wine barrel, nor "bechofnav", in a person's two palms held together.
A reason is attached to this list: "Mipnei she'ein memalin" - the drawing of the spring water, "ve'ein mekaddeshin", the mixing in of the ashes, "ve'ein mazin", and the sprinkling of the finished "mei chatas", are each of them valid "ella bichli", only by means of a genuine vessel. A potsherd, a barrel plug, a fragment broken off a utensil, or a pair of cupped palms can all hold liquid well enough, yet none of them carries the status of a vessel, and every stage of the chatas water demands one.
Tzamid Pasil Also Requires a Vessel
To close, the mishnah cites a matching rule from the realm of tumah: "Ein matzilin betzamid pasil" - a tightly sealed covering rescues its contents from impurity in one case only, "ella keilim", when the container is a vessel; "she'ein matzilin", for immunity from the impurity conveyed "miyad kli cheres", by an earthenware vessel, belongs to vessels alone.
Earthenware has a special quality: its outer surface is not susceptible to tumah. Other vessels of the kinds listed at the beginning of our mishnah are not susceptible to tumah at all. Such vessels, when closed with a lid that seals them tightly, shield what is inside them from becoming impure. But that protection is a property of a vessel. Whatever does not carry the name of a vessel gains nothing from a tight seal, and the contents inside it are not protected.
The thread running through the entire mishnah is therefore a single one: the materials may be humble, even cattle dung or a boat's hollow, but the object must be a real vessel. Where there is no vessel, there is neither kiddush of the chatas water nor protection from tumah.