Parah, Chapter 3, Mishnah 2. This chapter records the elaborate preparations that preceded the burning of the parah adumah, and in particular the extraordinary lengths taken to guarantee that everyone and everything involved would be absolutely free of any trace of tumah. Our Mishnah describes how the Chachamim arranged, years in advance, for a group of children who could draw the spring water for the mei chatas without the slightest suspicion of having contracted tumah from a corpse.
The Words of the Mishnah
The Mishnah opens by describing a piece of unusual construction: "Chatzeros hayu biYerushalayim" (there existed courtyards in Yerushalayim), and these were "benuyos al gabei sela" (put up directly upon bedrock), "vetachtehem chalul" (with an empty cavity left underneath the floor). The reason is stated at once: "mipnei kever hatehom", on account of a burial place sunk in the depths of the earth that nobody knows about.
"Umevi'im nashim ubaros": women who were expecting would be brought to these courtyards, "veyoldos sham", so that the birth itself took place inside them, "umegadlos sham es beneihen", and there the mothers went on rearing their sons.
"Umevi'im shevarim, veal gabeihen delasos, vetinokos yoshvin al gabeihen vechosos shel even biyadam." When the water was needed, oxen were brought with doors laid across their backs, and the children sat on top of the doors holding stone cups in their hands.
"Higi'u laShiloach, yardu umil'um, ve'alu veyashvu al gabeihen." When they arrived at the Shiloach they climbed down, filled the cups, climbed back up and again took their places on the doors.
"Rabbi Yose omer: mimkomo hayu meshalshel umemalei." Rabbi Yose holds that the child never descended at all: from where he sat he lowered the cup by a cord, filled it, and drew it back up.
Why Build on Rock with a Hollow Underneath
The concern throughout is kever hatehom, a forgotten grave hidden in the ground of which nobody is aware. Tumah that is sealed in beneath a covering, with no room to spread sideways, is called tumah retzutzah: it forces its way straight upward and defiles whatever stands above it. A child living in an ordinary house in Yerushalayim might therefore be rendered tamei without anyone ever knowing it.
The solution was to build these courtyards on solid rock, and to leave beneath the floor a hollow of at least a cubic tefach. Once there is an open space of that size, the tumah is no longer pressed and compacted; it rises into that empty space and stops there, and does not continue upward into the courtyard above. A child raised in such a courtyard was guaranteed never to have contracted tumah from a corpse.
The children were kept in these courtyards until the age of eight, so that throughout their formative years there was no cause for concern at all.
The Oxen and the Doors
That identical anxiety followed the children once they left the courtyard. Their errand was to bring spring water up from the Shiloach, the very water into which the ashes of the parah adumah would later be mixed, and the road itself was suspect: somewhere along the way a forgotten burial could be lying deep in the earth, unnoticed by anyone. The solution was to seat each child on a door that had been laid across the back of a tall ox. The broad surface of the door served as a partition separating the child from the ground below him, so that even if his route took him directly above a concealed burial site, the tumah had no way of reaching him.
The Dispute at the Shiloach
At the spring itself the Tanna Kamma permits the children to climb down and fill their cups in the normal way. There is no reasonable suspicion of a grave beneath the waters of the Shiloach, since people do not bury their dead in a riverbed.
Rabbi Yose is not satisfied even with that. In his view the child should remain on his door and lower the cup on a cord to draw the water, an added measure of caution taken purely for the honor of the mitzvah.
The picture the Mishnah paints is unforgettable: children born and raised in specially constructed courtyards, riding on doors on the backs of oxen, carrying stone cups down to the Shiloach, so that the waters of purification would be prepared in a state of perfect purity.