Sotah Chapter 9, Mishnah 5. In the previous mishnah we looked at the question of exactly where on the corpse the measuring is done, in order to determine which city is closest to it. Now, once the measuring has been completed and the nearest city has been established, the mishnah continues and describes the rest of the procedure.
"Niftru ziknei Yerushalayim":
The elders of Jerusalem, who are the elders who came from the great court - from the Sanhedrin - to carry out the measuring, now finish their task. Once the nearest city has been determined, they leave the area.
Bringing the calf:
From this point on the procedure passes to the "ziknei ha'ir" - the elders of the city that was found to be closest - and they "meviin eglas bakar" - bring a calf. The verse spells out its requirements:
"asher lo ubad bah" - that no work was done with it.
"asher lo mashchah be'ol" - that it never bore a yoke and never pulled with one.
The mishnah rules, however: "ve'ein hamum posel bah" - a blemish does not disqualify it. Note the novelty here: although with offerings a blemish is a disqualifying problem, with the eglah arufah a blemish does not disqualify.
"Umoridin osah lenachal eisan":
Both parts of this phrase need explanation. The word "nachal" can be understood as a valley, or as a stream of water - and in the Land of Israel there are many such streams, those wadis that sometimes have water in them and sometimes do not. About the second word the mishnah says: "ve'eisan kemashma'o" - meaning hard. From here there are two ways of understanding it:
It refers to a stream whose water flows with great force.
It does not refer to a stream of water at all, but to a valley whose ground is very hard. The hardness relates to the ground, not to water flowing with force.
And even though the Torah used the words "nachal eisan," the mishnah continues: "af al pi she'eino eisan kasher" - even if it lacks the quality of eisan, in whichever way the word is explained (whether regarding the water or the ground), the beheading is valid. The term "eisan" is a matter of performing the mitzvah in the ideal manner - this is the preferred way to carry it out, but it is not a binding requirement.
The beheading and the prohibition on the site:
Once the calf has been brought down there, they take a cleaver and behead it from behind, breaking its neck. The place where the beheading was performed becomes forbidden from that time on: it may not be sown, and no work may be done there and its ground may not be cultivated.
Nevertheless, it is permitted to comb flax there and to chisel stones there. The rule is that one may make use of the area as long as the ground itself is not being used, in the way that it is used in sowing or in digging into the earth.
In summary: in this mishnah we learned the continuation of the eglah arufah procedure: the elders of Jerusalem take their leave after the measuring, and the elders of the nearest city bring a calf with which no work has been done and which has not pulled with a yoke, while a blemish does not disqualify it. We looked at the meaning of "nachal eisan" and at the fact that it is not a requirement but the ideal way of performing the mitzvah, and finally at the beheading with a cleaver from behind the head and at the prohibition against working the ground at the site of the beheading - as opposed to the permission to comb flax and chisel stones there, since these do not involve use of the ground itself.