(Mishnah): One who cannot make his dough in Taharah, he makes it Kavin (each dough is a Kav, i.e. less than the Shi'ur of Chalah), and does not make it b'Tum'ah.

R. Akiva says, he makes it b'Tum'ah, and does not make it Kavin, for just like he calls [declares Chalah] for Tahor, he calls for Temei'ah.

To this [a Tahor dough] he declares Chalah with Shem (Hash-m's name, i.e. in a Brachah - R. SHLOMO SIRILIYO), and to this [a Tamei dough] he declares Chalah with Shem, but Kavim have no Chalah with Shem.

If one makes his dough Kavin, and they touched each other, they are exempt from Chalah until Yashochu (they touch, and if one separates them, part of one will stick to the other).

R. Eliezer says, if one removes [loaves from the wall of the oven] and puts them in a basket, the basket joins them for Chalah.

(Gemara) Question: [Above (12b), we said that to separate Chalah b'Taharah, one must go four Mil. Does this mean that if he can go] less than four Mil [and separate b'Taharah], he does it b'Taharah, but if he would need to go four Mil, he may make it Kavin? Or, he must go four Mil to do it b'Taharah, but if he would need to go more than four Mil, he may make it Kavin?

Answer: We learn from the following. R. Chiya bar Va said, e.g. [from here] to Kisarin [one must go to do his dough b'Taharah]. Is not Kisarin four Mil away? This teaches that four Mil, he does it b'Taharah, and more than four Mil, he may make it Kavin. (HA'GAON RAV C. KANIEVSKY, SHLITA - R. Chiya bar Va was in Tiverya. Presumably, it was four Mil from the gate of one city to the other. (PF) Alternatively, anyone in Tiverya considered Kisarin to be four Mil away, even though the true distance depended on from where in Tiverya he begins. This Halachah depends on a person's estimation of the distance!)

R. Ami ruled in Kefar Shamai to make a big dough b'Tum'ah.

Question: There was less than four Mil [to where they could do b'Taharah]!

Answer: Since a river interrupted (it was a toil to cross it), it is as if there was [more than] four Mil.

Question: [Did he rule unlike Chachamim in our Mishnah,] like R. Akiva?! R. Akiva says, he makes it b'Tum'ah, and does not make it Kavin [and Chachamim argue]!

Answer: It was a big dough, and [if not for the river] he would have preferred to go far (more than four Mil to do it b'Taharah) rather than do it Kavin. (Chachamim did not burden one to go more than four Mil. All the more so they would not burden to do it Kavin, if this is more toil for him than going four Mil - GRA.)

Question: R. Akiva contradicts himself! There (below, 4:2) he says that one takes Chalah from a Kav [and it is Chalah], and here he says so [that doing it Kavin exempts]?!

Answer: There, b'Di'eved (if he took Chalah, it is Chalah). Here, l'Chatchilah (one does not separate from a Kav).

(R. Yonah citing R. Chiyah citing R. Yochanan, and R. Yosi citing R. Imi citing R. Yochanan): [R. Eliezer says that if he put them in a basket, the basket joins them] - this is if Nashchu.

(Beraisa): Some teach that the basket joins, but the oven does not join, and some teach that the oven joins, but a basket does not join.

(R. Yochanan): If Nashchu, here and here (a basket and oven both) join. Without Nashchu, here and here do not join;

The Beraisa discusses big loaves of Bavel. (They rest on top of each other; it is as if Nashchu. Some teach that only the basket joins, and some teach that only the oven joins.)