(Mishnah): Terumah (and Ma'aser) may not be taken from a species on a different species. If this was done, it does not take effect.

Question: What is the source of this?

Answer (R. Ami): "Kol Chelev Yitzhar v'Chol Chelev Tirosh v'Dagan" - give Chelev (the best) of each.

Question: This teaches that Yitzhar (olives) and Sirosh (grapes) must be tithed separately. What is the source for Sirosh and Dagen (it says "Chelev" once for both of them), or for different kinds of Degen (grain)?

Answer: We learn from a Kal va'Chomer;

Grapes and olives are not Kilayim (forbidden mid'Oraisa to plant) with each other, yet they must be tithed separately. Grapes and grain, or different kinds of grain, which are Kilayim with each other, all the more so they must be tithed separately!

Question: According to R. Yoshiyah, Kilayim (Tosfos - Kilai ha'Kerem, but R. Yoshiyah agrees that Kilai Zeraim applies to two species) does not apply unless one sows together grape seeds together with (two other diverse seeds, e.g.) wheat and barley (so we cannot make this Kal va'Chomer). How can he answer?

Answer: We can still make a Kal va'Chomer:

Grapes and olives are not Kilayim with each other, even if a third species is added, yet they must be tithed separately. Grapes and grain, or different kinds of grain, which are Kilayim with each other when there is a third species, all the more so they must be tithed separately!

Question: What is the source that other diverse species must be tithed separately?

Terumah and Ma'aser applies to other species only mid'Rabanan. Chachamim enact laws similar to mid'Oraisa laws, diverse species must be tithed separately.

Question (Rava bar Rav Chanan): If so, we should be able to tithe all (Tahor) Behemos together, for it says "v'Chol Masar Bakar va'Tzon"! (There is no additional 'Ma'aser' written regarding Tzon to teach that it must be tithed by itself.)

Answer (Abaye): "Ha'Asiri" written after Tzon is extra. We use it to teach that it must be tithed by itself, as if it said 'Ma'aser Tzon'.

Question: We should say that goats and sheep must be tithed separately (from a Kal va'Chomer. Old and new animals must be tithed separately, even though they are not Kilayim with each other. Goats and sheep are Kilayim with each other, all the more so they must be tithed separately)!

Answer #1: "Tzon" permits tithing all Tzon together.

Question: We should likewise expound "v'Chol... v'Dagen" to permit tithing all grain together!

Answer #1 (Abaye and R. Ila'a): It says "Reishisam" (plural, to teach that each species of grain must be tithed by itself).

Answer #2 (Rava): We need not expound "Reishisam", for "v'Chol... v'Dagan" does not connote that all grains may be tithed together;

"Tzon" permits tithing all Tzon together, for otherwise, the Torah could have written only 'v'Chol Masar Behemah.' (The Kal va'Chomer from new and old would obligate tithing different species separately);

Suggestion: Perhaps "Tzon" is needed to exclude Chayos!

Rejection: A Gezerah Shavah "Tachas-Tachas" from Kodshim excludes Chayos.

Conclusion: "Bakar va'Tzon" were written to teach (by inference) that only they may not be tithed together, but all Tzon may be tithed together.

However, we cannot say that 'Dagan' was written to teach that grain may not be tithed with grapes or oil, but all grains may be tithed together. It is needed to exclude other species from Ma'aser! (The Rambam obligates mid'Oraisa almost all produce, except for spices and some vegetables. He is forced to say that "Tirosh v'Yitzhar" includes all fruits, and 'other species' refers to vegetables. This is difficult - Chazon Ish Shevi'is 7:23 DH v'Harbeh.)

Question (Rav Huna brei d'Rav Noson): Perhaps "Bakar va'Tzon" were written to permit tithing them together!

Version #1 - Answer (Mar Zutra brei d'Rav Nachman): Rava learns like Abaye. "Ha'Asiri" is written after Tzon, to teach that it must be tithed by itself.

Version #2 (Rava): Even without "ha'Asiri", we know that Tzon must be tithed by itself, for Ma'aser Behemah is equated to Ma'aser of grain ("Aser Ta'aser");

Just like Ma'aser of grain may not be taken from one species on another, also Ma'aser Behemah.

Question: Rava contradicts what he expounded above (end of 53b), that Ma'aser of grain and animals are equated only regarding new and old!

Answer #1: Rava retracted from what he said above.

Answer #2: One of these was taught by Rav Papa (his Talmid, who was Rosh Yeshivah after Rava. People often mistakenly attributed Rav Papa's teachings to Rava.)

(Mishnah): Animals (born in one year) join for Ma'aser Behemah if the distance between them is up to Malei Regel Behemah Ro'eh (the distance that grazing animals typically stray);

This is 16 Mil. (A Mil is 2000 Amos, about one kilometer.)

If the animals are 32 Mil apart, they do not join. (This will be explained.)

If there were animals in the middle, he brings the others there and takes Ma'aser. (Really, he may tithe them anywhere.)

R. Meir says, the Yarden (Jordan River) separates for Ma'aser Behemah.

(Gemara) Question: What is the source of this?

Answer (Rabah bar Shila): "Od Ta'avornah ha'Tzon Al Yedei Moneh" - Chachamim know that a shepherd can see up to 16 Mil.

(Mishnah): If the animals are 32 Mil apart, they do not join.

Inference: If they are less than 32 Mil apart, they join.

Contradiction: The previous clause said that they join only until 16 Mil!

Answer: Sixteen Mil was said only due to the next clause. If there were animals in the middle, he brings the others there and takes Ma'aser. (All the animals must be within 16 Mil of the middle place).

Question: How many animals must be in the middle?

Answer #1 (Rav): Those in the middle must be able to join with those on either side to make 10, e.g. five in the middle and five on each side;

Answer #2 (Shmuel): Even if there is one in the middle and five on each side (those on both sides are needed to make 10, the one in the middle does not help at all), we consider the shepherd to be in the middle. He is a "Moneh" (so they join.)