Part of the standard morning prayer-service includes a Mishna (Pe’a 1:1), which lists a number of mitzvot she-ein lahem shi’ur – commandments that have no limit. Among the commandments that appear on this list are:
Pe’a – leaving a corner of one’s field for the poor
Bikurim – first fruits that are brought to Jerusalem
Re’ayon – Appearing in the Temple
Gemilut Hasadim – Acts of loving-kindness, like visiting the sick, burying the dead, etc.
Talmud Torah – Torah study
Our Gemara quotes this Mishna in an attempt to examine and define the mitzvah of re’ayon – visiting the Temple. On the holiday itself it is clear that everyone is required to visit the Temple with a sacrifice in hand. The question is whether on Hol HaMoed a visit to the Temple necessitates an accompanying korban. Rabbi Yohanan defines this commandment of re’ayon as entering the Temple, so someone coming without a sacrifice would also be admitted; Reish Lakish explains it to refer to bringing sacrifices, and everyone entering the mikdash would be obligated to bring a korban with him.
Aside from this disagreement, we find that Rabbi Yohanan teaches how until Rabbi Oshaya came and taught otherwise, the first assumption was that while re’ayon has no upper limit, there was a minimum requirement to fulfill the mitzva. Rabbi Oshaya clarified that there is no Biblical minimum, and the requirement to bring sacrifices of a specific minimum value is a Rabbinic enactment.
Although our Gemara seems to indicate that Rabbi Yohanan accepts Rabbi Oshaya’s approach, in the Talmud Yerushalmi it is clear that there are serious differences between them with regard to this issue. According to Rabbi Oshaya, in all cases where the Torah does not attach a specific shi’ur (measurement), any minimum or maximum requirement that we find is only Rabbinic in nature. Rabbi Yohanan, on the other hand, believes that shi’urim are halakha le-Moshe mi-Sinai – an oral tradition given to Moses on Mount Sinai and handed down through the generations – which gives them the strength of Biblical requirements.