Shabbat 2B

ידיעות הטומאה, שתים שהן ארבע.

Similarly, with regard to awareness of ritual impurity, there are two cases that comprise 4. It is prohibited for one who is ritually impure to enter the Temple or to consume a consecrated item. However, one who unwittingly violates this serious prohibition is obligated to bring a sacrifice for his transgression only if he was clearly aware of his ritually impure status both before committing the transgression and after that. The two cases of unwitting transgression in this area are: One who was aware and then forgot that he is ritually impure, and then either ate consecrated meat or entered the Temple, and subsequently recalled that he was ritually impure. Two additional cases are: One who was aware of his ritually impure status but was unaware that the food he was about to eat was consecrated and ate it, or he was unaware that he was about to enter the Temple and entered it.

מראות נגעים, שנים שהן ארבעה.

Signs of affliction by tzara'at are two that comprise 4. The Torah (Leviticus 13) mentions two types of signs of affliction with regard to tzara'at, baheret and se’et. Two additional, secondary signs of affliction were added. They are not as white as those delineated in the Torah. Consequently, there are derivatives of both baheret and se’et.

יציאות השבת, שתים שהן ארבע.

The Mishnah in Shevuot also mentions that the acts of carrying out on Shabbat are two basic actions that comprise 4.

מאי שנא הכא דתני ״שתים שהן ארבע בפנים ושתים שהן ארבע בחוץ״, ומאי שנא התם דתני ״שתים שהן ארבע״ ותו לא?

The Talmud asks: What is different here that our Mishnah teaches: Two that comprise 4 inside and two that comprise 4 outside, and what is different there, in tractate Shevuot, that the Mishnah teaches with regard to transfers on Shabbat: Two that comprise 4, and nothing more?