1)

(a)If someone separates more than one tenth of his crops as Ma'aser Rishon - his crops are rectified, but the Ma'aser that he gives to the Levi contains Tevel (since whatever is in excess of a tenth does not become Ma'aser).

(b)This will not be the case if someone gives Terumah which is more than a fortieth - because Terumah anyway has a scale and is not fixed.

(c)'Kol she'Eino be'Zeh Achar Zeh, Afilu be'Bas Achas Eino' does not apply to giving Ma'aser - because it is possible to declare Ma'aser on a fifth of one's crop, by declaring half of each grain Ma'aser (whereas by Eruv, the four Amos must be together).

(d)Nor does 'Kol she'Eino be'Zeh Achar Zeh' etc apply to Ma'aser Behemah, because Ma'aser Behemah 'be'Zeh Achar Zeh' is effective - in a case of someone who made a mistake and declared the ninth to be the tenth, the tenth, the ninth, and the eleventh, the tenth (in which case, we learn from Pesukim, all three are Kadosh mi'd'Oraysa).

2)

(a)If he declared the tenth animal to be the ninth, and the eleventh, the tenth - he brings the eleventh as a Shelamim.

(b)Shelamim can be redeemed when they become blemished, Ma'aser cannot; and the Temurah of a Shelamim is sacrificed, whereas that of Ma'aser is not.

(c)If someone simultaneously declared the two animals to be the tenth, and does not now know which one is Ma'aser, and which Shelamim -

1. ... he leans his hands on both animals and waves them, but without reciting a Berachah.

2. ... he brings the drink-offering that is appropriate for a Shelamim - on which he stipulates that it should be effective on whichever one is the Shelamim.

3)

(a)A Korban Todah was accompanied by forty loaves.

(b)If the owner, forgetting that he has already designated forty loaves, designates another forty - the second set of forty is not Kadosh.

(c)Chizkiyah holds that when someone Shechted his Todah on eighty loaves - forty out of the eighty are Kadosh.

(d)Rabah explains that when the owner specifically declared that forty out of the eighty should be Kadosh, then everyone agrees that forty of them are Kadosh (as we explained at the end of the previous Amud). When he says that forty will only be Kadosh if all eighty are Kadosh, then everyone will agree that none of the loaves are Kadosh. The Machlokes between Chizkiyah and Rebbi Yochanan is confined to a case where he simply declared forty loaves to be Kadosh. Chizkiyah holds that he means to make forty loaves Kadosh and the rest as a sort of collateral (in case something happens to the first forty) - which is effective because it is similar to the case of forty loaves out of the eighty. Whereas Rebbi Yochanan maintains that his intention is to bring a large Korban consisting of eighty loaves - a classical case of 'bas Achas', which is not effective.

4)

(a)The reason that, in Abaye's opinion, Rav will agree that, when the branches span less than twelve Amos, he will be Koneh Shevisah (even according to Rebbi Meir) - is because then, it is possible to pick a place of residence of four Amos (i.e. the middle four Amos), which will incorporate at least a part of any of the three sets of four Amos that he meant to designate: the outer four, the middle four or the inner four.

(b)Rav Huna Brei de'Rav Yehoshua however, objects to this - because who says that he had in mind the middle four Amos (which incorporate both outer sets of four Amos)? Perhaps he had in mind the inner four Amos (which is not included in the outer four), or vice-versa?

(c)Rav Huna Brei de'Rav Yehoshua therefore, amends Abaye's statement to read that Rav's statement is confined to when the branches of the tree span at least eight Amos, because then, neither of the sets of four Amos overlaps the other one, and who knows which of the two sets he was referring to? But if the branches spanned less than eight Amos, then Rav will agree that (even according to Rebbi Meir) he will be Koneh Shevisah. Because then, each of the two sets of four Amos overlaps the other. Consequently, whichever of the two he was referring to, incorporated at least a small section of the other set of four Amos as well.

5)

(a)Rav will agree that one is Koneh Shevisah from a distance, even by an area that is more than eight Amos wide and even according to Rebbi Meir - if the area is enclosed by walls - since the entire area is considered as if it was four Amos.

(b)By an area which is (either Hukaf le'Dirah or) not more than a Beis Sasayim (which is considered as if it was four Amos), he will be permitted to walk the entire area plus two thousand Amos; whereas if the area is more than a Beis Sasayim, as well as being not Hukaf le'Dirah, he has only two thousand Amos including the area itself.

(c)If one of two travelers knows of a certain landmark within two thousand Amos from the point where they are standing, and from their house, which is two thousand Amos beyond it in the opposite direction - then the one who does not recognize it appoints the one who does as his Sheli'ach to be Koneh Shevisah on behalf of both of them.

6)

(a)According to Shmuel, the Beraisa, which forbids walking even one step outside the four Amos where he now is, when he fixes his residence in an undefined spot (e.g. under a tree) - speaks when the trunk of the tree is two thousand and four Amos from where he is. There, even Shmuel will agree that he is not Koneh Shevisah, since he may have fixed the four Amos which are on the far side of the tree, a point which is beyond his Techum.

7)

(a)If two servants for example, placed an Eruv on behalf of their master, one in the north, and the other, in the south - he is permitted to walk only within the area in which the two Eruvin overlap.

(b)According to Rav, whenever the border is not clearly demarcated, it is forbidden to go more than four Amos - so how can the Tana of the Beraisa permit him to walk within the area that the two (undefined Eruvin) overlap?

(c)Rav is considered a Tana and has the power to argue with a Beraisa.