(Mishnah): If a Kohen or a Levi received a field from a Jew as a sharecropper - just as they divide the Chulin (with the land owner), so too they divide the Terumah. (They give the land owner his portion of Tevel and he gives its Terumah and Maaser to whichever Kohen and Levi he wishes.)

(R. Eliezer): Those portions must go to them, because they accepted the field under this condition.

(Gemara) (Rabbanan to R. Eliezer): How did the Kohen and Levi acquire these portions?

(R. Eliezer to Rabbanan): Don't you agree that if they made a stipulation between them, that the Kohen and Levi would acquire them? But then you could ask the same question - how do they acquire it? It's as if the owner told the Kohen/Levi, "Detach part of the crop (as I will separate its Terumah and Maaser later)".

(Rabbanan to R. Eliezer): The wheel of a carriage doesn't itself have a wheel (that makes it move)! (Even if he explicitly made this stipulation, you would have needed to say 'it's as if he said 'Detach...' - so now that he didn't even make the stipulation - you must make two assumptions - firstly, that it's as if he said one and secondly, it's as if he said 'Detach'; and we don't say two 'as if's.)

Tosefta: If a Kohen received a field in Kablanus from a Kohen or a Levi from a Levi, or a Yisrael from a Yisrael, each takes the tithe in his portion.

Question: According to which opinion does this need to be said? According to R. Eliezer (of our Mishnah) - even though R. Eliezer said that 'those portions must go to them, because they accepted the field under this condition', here both parties receive the tithes because they are both of the same category (e.g. Kohanim).

Tosefta (Demai Ch. 7): If a Yisrael received a field in Kablanus from a Kohen, the Yisrael can stipulate that he will be able to give the tithes to whoever he wishes; but he may not stipulate that it should be 'yours or mine and yours'. (Note: The text of the Tosefta is changed here by the Chazon Ish.)

If a Kohen received a field in Kablanus from a Yisrael, the Kohen can stipulate that the tithes are his; but he may not stipulate that it should be 'yours or mine and yours'. But it is only prohibited when he didn't accept the field as Kablanus (for a certain proportion of the crops) but rather the Kohen will receive its tithes as payment; but if he did accept it as Kablanus and the owner also added the tithes, it is permitted.

Question: But either way, the tithes are going to the Kohen?!

Answer: Rather, he said, 'the half that is mine, is mine; and the half that is yours, let's divide it' - this is when the statement above applies that it is only prohibited when he didn't accept it as Kablanus etc.

If a Yisrael received a field in Kablanus from a Yisrael, on condition that the tithes should go to a certain Levite, it is prohibited. If he said, "...on condition that I will take them and give them to this Levite" - it is permitted.

Question: How is the second case different to the first?

Answer (R. Acha): The difference is - in the 1st case, it's as if he's selling the actual Maaseros. In the 2nd case, his stipulation isn't about the actual Maaseros; it's about his right to choose when giving them to a Kohen or Levi.

(R. Yosi disagrees): That's not the difference. The 2nd case is when he received it in the regular way of a Kablan - meaning for a portion of the produce; so it's not viewed like a Kohen helping in the granary.

R. Yosi is like R. Yochanan and Rav Acha is like R. Yosi bei R. Chanina - as R. Yosi bei Chanina said that a person gives his Maaseros in Tovas Hana'ah and R. Yochanan said that he does not.

Question: What's R. Yosi bei R. Chanina's source? The pasuk states (Bamidbar 5:10), "Everyone's holy things shall belong to him" - meaning that Tovas Hana'ah is his.

Question: How does, R. Yochanan use this pasuk? To instruct that he may give them to whoever he wishes (but that has no monetary value).