Explanation #1: The Makshan thought that "we fix the roads" does not include removing thorns. "Tikun" connotes fixing mounds and cavities. Therefore, he asked (that "all needs of the Rabim" teaches removing thorns);

We answered that all of these were explicitly taught, for they are included in "we fix..." (Therefore, "all needs of the Rabim" includes digging pits.)

Explanation #2: The Makshan was not so fluent in the Mishnah. He did not know that it says "we fix the roads."

R. Chananel's opinion: We cited this verse, which was written regarding Ma'akeh (the Mitzvah to build a wall around a roof), for it is a Michshol (there is concern for injury).

Inference: From the Mishnah with the Gemara, we can learn that one may not water land, except for what is Devar ha'Avud, lest the grain or trees planted in it get ruined.

The same applies to other Avodas Karka. It is forbidden during Chol ha'Moed.

Implied question: We say that one may water!

Answer: This is only from an irrigation channel that passes through the field itself. It is not excessive exertion.

One may fix pits and caves of an individual, and dig l'Chatchilah for a Rabim, since they need water. The Beraisa above says so, like I explained.

Explanation: [It is called only a hint] because the verse refers only to the future, but not to nowadays.

However, he answered that we can learn from there.

Explanation: According to you, who say that nowadays it is mid'Oraisa, if so, before Yechezkeil, Hash-m should have taught us that we must demarcate!

He answered that there are many matters that we hold that the Torah forbids, but they are not written in a verse;

Rather, they were a tradition until Yechezkeil came. The same applies here.

Explanation: Each one cited the verse that he thought of. They do not argue. It is normal that each thinks of something that his colleague did not think of.

Explanation: This is the Shabbos [of, or perhaps before] the festival, when they expounded and the entire city came to hear laws of the festival.

Explanation #1: This means that it does not require a marking.

Explanation #2: If the Beraisa discusses Yom Tov, we can explain that it is forbidden to mark, due to toil on Yom Tov. (Ya'avetz - here, "Yom Tov" refers to Chol ha'Moed.)

Explanation: the same applies to more than k'Se'orah. This is clear from the Gemara below that it is not Metamei b'Ohel.

Implied question: Why did the Gemara discuss [a bone] k'Se'orah?

Answer: This is the Shi'ur for Tum'as Maga. This is a tradition from Moshe from Sinai, like it says in Chulin (126a).

Examples: A spoon of a decayed Mes, like it says in Chulin (126b), a field in which a grave was plowed, like it says later in our Sugya [are not Metamei b'Ohel)].

Assertion: Even if there is a Safek Tum'ah that is Metamei b'Heset (through moving) without touching, it need not be marked;

This is because Heset is not common, that one step on a stick on which there is Tum'ah. Therefore, Chachamim did not obligate to mark due to Heset.

Explanation #1: It is near a cemetery. We have a Safek whether or not there is Tum'ah underneath.

Presumably we say that there is a Mes underneath, since it is a covert place. Therefore, one must mark it.

Explanation #2: We know Vadai that there is Tum'ah under one branch of the tree, and there is a space between one branch and another, and we do not know where it (the Tum'ah) is.

Explanation #3: We could also explain regarding rocks, that there are rocks near each other protruding from a wall [and there is Tum'ah under one of them...]

Explanation: Stam, we say that the plow reached to the Mes, and we do not establish a Tahor place to be Tamei due to Safek. (I.e. even where the Mes was, it is not Metamei b'Ohel.)

However, Chachamim were stringent due to the stringency of Taharos. Therefore, they were lenient, for there is not a Safek Torah;

They said [to be stringent], and they said [when to be lenient].

They did not regularly bury deeply, like nowadays. Therefore, we are not concerned lest the Mes was deep under the plow (and a Shi'ur of something with Tum'as Ohel remains there.)

Letter of the law, one should not even need to blow. It is merely a stringency of Taharos that Chachamim imposed in this matter.

Question #1: Why aren't we concerned lest there is a Mes in the ground that he does not touch, and it is Metamei b'Ohel?

Question #2: Alternatively, trees on the side towering [over the Beis ha'Peras] should be Metamei a person b'Ohel!

Answer to both questions: This shows that it is not Metamei b'Ohel.

Citation (Tosefta Ohalos 17): A field in which a grave was lost, one may not plant any [trees] in it.

Explanation #1: The case is, the field is proper for trees. We can say that presumably, had a grave not been lost there, they would have planted in it.

Explanation #2: Alternatively, we do not literally mean "it is known [that a grave was lost there." Really, it is a Safek.] Since the Reisha says "[if there are trees,] it is known [that a grave was plowed there]", also the Seifa says "it is known."

Support: We must say so according to Perush Rashi.