Sotah 097

5:
By the time we reach tannaïtic times it seems that the ceremony of the 'decapitated calf' is no longer effective. In a later mishnah in this chapter we shall learn that the ceremony was abolished, and the reason given was that there were now too many corpses. Whatever the reason we have seen that by their hermeneutic interpretations the sages had already attempted to severely limit the possible application of the law: it would not apply to corpses found buried, or to corpses found hanging from trees, or to corpses found floating on water – and those restrictions should have severely limited the possible application of the rule.

6:
But other considerations would permit an even greater restriction of the law. In Mishnaic times the population of Eretz-Israel was very much as it is today: a majority of the inhabitants are Jewish, and a very substantial minority of the inhabitants are not. Mostly, the Jewish and the non-Jewish elements of the population do not mix socially; some towns are of mixed population, but in most cases townships are either Jewish or non-Jewish. (During the early decades of the first century CE legislation was initiated by the sages which was designed to reduce socializing of Jews with non-Jews to a very great degree – the so-called 'eighteen decrees' enacted by the Sanhedrin.) This fact of human geography permits a further limitation of the law of the 'decapitated calf' – this time based not so much on hermeneutic interpretation (though that, of course, is provided) as on practical logic.

7:
If "the elders of the township" are to perform the ceremony it logically follows that the townships involved must be Jewish: the writ of "your elders, your judges" will not run in non-Jewish townships. Thus, if a corpse is found near to a non-Jewish township there ceremony is obviated. In his commentary on our present mishnah Rambam makes a point that I find very poignant in view of the present human geography of Eretz-Israel. He writes:

8:
Another reason for not observing the law of the 'decapitated calf' would be the fact that a town or village does not have a Bet Din to perform the ceremony. When we studied Tractate Sanhedrin we found in Chapter 1, Mishnah 6 the following:

9:
The 'maĥloket' between Rabbi Eli'ezer and Tanna Kamma is a non-starter, as Rambam points out in his commentary on this mishnah, it being impossible to arrive at a measurement in which both nearest settlements are exactly equidistant from the corpse. However, the Gemara [Bekhorot 18a] determines that if such a situation were to arise both townships equally share the cost of providing one calf only to be decapitated.

10:
The only real 'city' in Eretz-Israel in Mishnaic times was Jerusalem. And our mishnah teaches that if Jerusalem was the town nearest to the found corpse (as statistically must have been most likely) the ceremony of the 'decapitated calf' was not to be observed! The hermeneutic reasoning is that the Torah [Deuteronomy 21:1] says that the corpse must be found "in the land which God gives you as your possession". Initially, Jerusalem was not allocated to any of the tribes, and was annexed to Judah by King David.