We have already learned (in the first Mishna in this perek – 70a) that a kohen who is an arel – a Jewish man who has not been circumcised – cannot eat teruma. The Gemara on our daf discusses the case of a mashukh – a person who had a brit mila and then had his skin stretched back so that it would appear to be a foreskin, in order to hide his circumcision. This type of operation was done during certain times in Jewish history – for example, under Greek/Hellenistic rule – when being circumcised was an embarrassment for someone who was interested in assimilating into the dominant culture, which viewed circumcision as mutilation. It should be noted that under the Greeks, sporting events – including the original Olympic Games – were held with the participants unclothed.
Rav Huna rules that, on a biblical level, someone who has undergone this operation and has hidden his brit mila is still considered circumcised; nevertheless the Rabbis ruled that such a person should undergo a second circumcision. Furthermore, the Gemara reports that during the rule of bar Koziva, many people who had hidden their brit mila arranged to undergo a second circumcision.
The individual who is known to the Gemara as bar Koziva is the same person who is known to us – as he was called by Rabbi Akiva – as bar Kokheva. In letters written by him that have been unearthed in archaeological excavations, we find that he signed his name Shimon ben Kosba. Apparently, the other names that he had “played off” of his actual name. His supporters called him bar Kohkeva – “the son of the star” – basing themselves on the passage recited by the prophet, Bilam (Bamidbar 24:17), darakh kokhav mi-Yaakov. Those who opposed his revolt – especially after it failed – called him bar Koziva – “the son of falsehood.”
One of the underlying causes of the bar Kokheva revolt was the edict of the Caesar forbidding circumcision around 130 CE. From our Gemara we see that there were also people who tried to hide their circumcisions, an act that they later removed under the inspiration of bar Kokheva.