Question: (The Mishnah taught that if he cancelled his authorization, if it was before the Terumah was separated, the Terumah is invalid.) Doesn't this disagree with Reish Lakish's teaching that one cannot verbally cancel a messenger (since words cannot come and cancel words)...?

Answer: When he sent the messenger, he said, "Go and separate the Terumah in the northern side'' and the owner went himself and separated in the south.

(R. Yochanan): Pressed grapes - once the workers have trodden them by walking on the beam this way and that, the wine causes the grapes to be able to contract Tumah and the entire pit is immediately assumed to be Tamei as a Tamei person might have touched it.

Question (Baraisa): 'If workers separated Terumah from the pit (without the knowledge of the owner), it is not valid. If the pit was small (where Tumah is more common) or others there had shaken their hands inside it, the Terumah is valid (as the owner would prefer that the Terumah had been taken before it became Tamei).' This means that if others had not shaken their hands there, it is invalid Terumah...?

Answer: R. Yochanan was discussing wine and the Baraisa was discussing oil.

Rebuttal: Wine and oil are the same, but Tumah is common with wine (as people want to taste it) and not with oil.

(Baraisa): When is Terumah separated from grapes? When they have been trodden this way and that. From when is there a concern that they have become Tamei? Beis Shammai says, "From when Maaser Sheni is taken''. Beis Hillel says "From when Maaser Rishon is taken''.

(R. Yosi): The Halacha follows Beis Shammai, but many are accustomed to be stringent like Beis Hillel.

(R. Shimon): Beis Shammai should be followed in Temple times (since Maaser Sheni was eaten in Taharah in Yerushalayim) and Beis Hillel nowadays (as people are not careful from Tumah).

(Chachamim): The Halacha does not follow Beis Shammai or Beis Hillel. Rather, he should first separate Terumah and Terumas Maaser to prevent it from becoming Tamei, and immediately after that, we assume that the entire pit has become Tamei.

(Tosefta): When is Terumah separated from olives? One Tana taught that it's from when the olives are crushed in the millstone for their oil (after the beams had already rested on top of the olives). Another Tana taught that it's from when the beams are placed on them.

Question: It is fine according to the Tana that placing the beams is the completion of their work (to be obligated in Terumah), but according to the Tana that it's only from when the olives are crushed (but after the beams have rested on them, they still aren't yet obligated), didn't R. Yochanan say (earlier (c)) concerning pressed grapes - once the workers have trodden them by walking on the beam this way and that, the entire pit is immediately assumed to be Tamei (which indicates that the completion of their work is after the beams have rested)?

Answer: That was discussing wine and our discussion is about oil.

Question: Aren't wine and oil the same?

Answer: It is common for wine to become Tamei (since people take it to drink), but it is uncommon for oil to become Tamei.

(R. Chiya bar Ada): In both cases, Tumah is common, but it is more common with wine.

Baraisa (R. Yosi b'R. Yehuda): If the owner wishes, he can bring olives and put them under the beam and then immediately separate Terumah.

(Chachamim to R. Yosi b'R. Yehuda): Olives are different from grapes - grapes are soft and are easily squeezed; olives are hard and are not easily squeezed, so Chazal delayed their obligation to separate Terumah until after the oil has been squeezed out.