The second perek (=chapter) of Masechet Bekhorot began on yesterday’s daf (=page). With it the Gemara turns its attention to the laws of firstborn kosher animals that are ordinarily supposed to be brought as sacrifices in the Temple.
According to the Mishnah on today’s daf (=page) if an animal that had a blemish that precluded it from being brought as a sacrifice was consecrated by its owner and then was redeemed, it becomes an ordinary animal. Examples of the practical effect of this include the obligation to set aside its firstborn as a bekhor and that when it is slaughtered, it is not considered kodashim ba-hutz – slaughtering a consecrated animal outside of the Temple precincts.
The Gemara notes that Rabbi Elazar offered an alternative ruling on the last case. He rules that someone who slaughters a consecrated animal with a blemish outside of the Temple precincts is held liable, but only if this took place in a time period when bamot – private altars – were permitted.
When were private altars permitted?
When the Children of Israel crossed the Jordan River into Israel and came to Gilgal, bamot were permitted: the most sacred sacrifices were still only eaten within the curtains of the mishkan, but lesser sacrifices were eaten anywhere. When they came to Shiloh and established the mishkan there, bamot were again forbidden. The Tabernacle in Shiloh had no roof, but consisted of a stone edifice veiled with curtains, and that was the menuhah – the ‘rest’ – referred to by the Torah(see Sefer Devarim 12:9, which permits sacrifices outside of the Temple until the people reach a place of menuhah ve-nahalah – rest and inheritance). Shiloh played the role of the City of Jerusalem in that holy sacrifices were eaten in the mishkan, within the curtains, and lesser sacrifices and second tithe were eaten wherever the city of Shiloh could be seen.
After Shiloh was destroyed (see Sefer Shmuel I, Chapter 4 and Sefer Yirmiyahu 7:12), the mishkan was moved to Nov and to Givon, and at that point bamot were again permitted. Still, the most holy sacrifices were only eaten within the curtains of the Tabernacle, but lesser sacrifices and the second tithe were permitted to be eaten in all the cities of Israel.
Finally, when Jerusalem was established as the center of Jewish worship with the erection of the Temple, bamot were forbidden and were never again permitted, and that was the ‘inheritance’ (again, see Sefer Devarim 12:9, which permits sacrifices outside of the Temple until the people reach a place of menuhah ve-nahalah – rest and inheritance). Most holy sacrifices were eaten within the curtains of the Temple, and lesser sacrifices and the second tithe were limited to within the walls of Jerusalem.