Horayos 1:2 - 1:3

Rabbi Shimon exempts him – Because the ruling had reached the majority of the community.

Rabbi Elezar declares this case doubtful – Since he should inquire any time there are new rulings by the beit din and he didn’t inquire, this is similar to the case where he is in doubt whether it is a sin or not and he brings an asham talui. The law is according to Rabbi Elezar’s opinion.

Which case may be regarded doubtful – For example, like what Rabbi Elezar said, the matter being discussed is that he was satisfied with the ruling, whether a sin or not a sin and he is obligated to bring an asham talui.

One who remains at home – When a person is at home in the country where the beit din ruled, he could have heard that the beit din reversed its ruling.

If he went abroad – This does not necessarily mean he already set out, but if he was preparing to travel but had not yet left, Rabbi Akiva holds the opinion that a person who is preparing for a journey will not be able to inquire whether the beit din reversed its ruling and he is exempt from bringing an asham talui. Ben Azzai thinks that since he had not yet set out on the journey, he should have inquired. This is the disagreement in the Gemara. And the law goes according to Rabbi Akiva’s opinion.

An entire principle has to be uprooted – The essence of the commandment, as is explained.

They are exempt – As it is written (Leviticus 4) “the thing being hidden”, read it as if it said “and it was hidden from the thing, i.e. part of it [the commandment], not its entirety.

But if a man has relations with a woman that awaits a day corresponding to a day he is exempt – The gemara answers that she who keeps a day for each day, as it is written in the Torah (Leviticus 15) “she shall count for herself” comes to teach that she counts one day for each day [of bleeding], and if something is written in the Torah the beit din does not bring a sacrifice. The Gemara explains, for example, that they are talking about a zava, which is only a case during the day, i.e., when she sees blood during the day and not when she sees at night, as it is written there, “all the days of her issue.”

If a man carries anything from a private domain to a public domain he is exempt – It is forbidden to take things in and out, as it is written (Exodus 16) “let no man go out of his place,” but throwing and proffering are permitted.

Bows down [to an idol] he is exempt - They state that bowing down means stretching out arms and legs and is forbidden, as it is written (Exodus 34) “you shall bow down to no other god” but if the bowing is without stretching out arms and legs it is permitted. The rule of the matter is, not beit din is obligated until it rules on a matter on which the Sadducees do not concur. But if it rules on a matter on which the Sadducees concur, the beit din is exempt from a communal sacrifice, and the majority that acts according to the beit din’s ruling, each one must bring a sacrifice for his erroneous transgression. What is the reason? Go read it in the school house [i.e. every school child understands].