The Beraisa learns from the three Pesukim "va'Hashem Beirach es Avraham ba'Kol" (Chayei Sarah); "va'Ochal mi'Kol" (Toldos) and "ve'Chi Yesh Li Kol" (Vayishlach) - that, at some stage during their lives, Hash-m gave the Three Avos a taste of Olam ha'Ba already in this world (and these Peaukim also serve as the basis for the statements that follow).

The Tana possibly learns from the Pasuk of "ve'Libi Challal be'Kirbi" - that, as well as the Avos, David, at some stage in his life, was no longer controlled by his Yetzer-ha'Ra.

Alternatively, we might explain the latter Pasuk to mean - that David's (physical) heart was dead inside him (referring to the many Tzaros that he constantly experienced.

The Tana says that the Avos plus Moshe, Aharon and Miriam - died with a kiss from Hash-m (and not at the hands of the Angel of Death.

The Tana includes the Avos in this list because of "ba'Kol", "mi'Kol", "Kol"; Moshe and Aharon, because the Torah writes by both of them "al-Pi Hash-m", and Miriam - because of the 'Gezeirah-Shavah' "Sham" "Sham" from Moshe ("va'Tikaver Sham" and "va'Yamas Sham al-Pi Hash-m").

The reason that the Torah does not say "al-Pi Hash-m" in connection with her, too is - out of respect for Hash-m.

What the above six and Binyamin ben Ya'akov have in common is - that the worms did not have any power over their bodies in the grave (see Tosfos DH 'Shiv'ah').

We know this to be the case by ...

... Moshe, Aharon and Miriam - from the fact that they were not killed by the Angel of Death, whose sword is tipped with the 'poison' that causes the body to decay and become eaten by worms.

... Binyamin ben Ya'akov - from the Pasuk in ve'Zos-ha'Berachah "Yishkon la'Vetach alav".

And from the Pasuk "Af Besari Yishkon la'Vetach", the Tana learns - that David might belong in this list too.

This Pasuk is not such a good proof however - since it may have been a Tefilah on the part of David, a Tefilah that was not accepted.

Binyamin ben Ya'akov, Amram, Moshe's father, Yishai, David's father and Kil'av his son, have in common the fact - that they all died because of the sin of Adam ('be'Ityo shel Nachash' [as a result of the plot of the Snake), but not on account of any sin that they performed, since they all never sinned.

The first three - are based on tradition ('Halachah le'Moshe mi'Sinai').

Based on the Pasuk in Divrei Hayamim, Tzeruyah's three children were called Avshai (better known as Avishai), Yo'av and Asa'el. The name of Tzeruyah's ...

... sister was - Avigayil (not to be confused with David ha'Melech's wife of the same name).

... famous brother was - David.

The Pasuk in Shmuel refers to her as "bas Nachash" - to teach us that Amram her father, too, died without sin ('be'Ityo shel Nachash').

Our Mishnah permits Reuven to dig a pit, trench, cave or stream of water at a distance of - not less than three Tefachim from Shimon's pit.

The same applies to digging a 'Nivreches Kovsin' - which is a square pit one Amah or more deep in which rain water gathers, and which is then used for washing clothes. In fact, it comprises two pits, one for soaking (in dog's droppings) for a day or two; the other, for washing.

The three-Tefach distance is necessary - because otherwise, the actual digging of Reuven's pit would weaken the walls of Shimon's.

In order to prevent damaging Shimon's pit, Reuven is also obligated - to cement his own pit with lime.

The Mishnah forbids Reuven to place his Gefes (the waste of the olives from the olive-press), manure, salt, lime or flint-rocks within three Tefachim of Shimon's wall.

In addition, to safeguard the wall - he must cement the pit in which they are lying with lime.

The Tana permits Reuven to place his seeds and plow, as well as to urinate - a distance of at least three Tefachim away from Shimon's wall.

A mill harms the wall next to which it is placed - via the vibrations.

The Mishnah also forbids Reuven to place his Shechev (the lower mill-stone) within three Tefachim away from Shimon's wall - and the Rechev (the upper mill-stone), within four.

An oven harms the wall next to which it is placed - by means of the heat that emanates from it.

The purpose of the base of cement and bricks that they would make for a Tanur (an earthenware high-temperature oven with its opening on top) is - to prevent the base of the actual oven from cooling down as a result of its contact with the earth.

The base is wider at its base and narrower at the top (like the Tanur which it supports).

Reuven is forbidden to place the Kalya (the foot of that base) within three Tefachim of Shimon's wall; the Safah (its upper-edge) - within four.

Abaye (or Rav Yehudah) accounts for the fact that the Tana begins talking about Reuven digging a pit near Shimon's pit, and ends with how far he must keep away from his wall - by extrapolating from here that it is not the pit itself from which Reuven must keep his distance, but the wall of the pit.

Had the Tana merely said that he must keep away from Shimon's pit, he would anyway have had to mean from the wall of the pit, and not from the pit itself - because then he would not be keeping any distance at all (see Rashash, though it is unclear why that is).

The reason that the Tana nevertheless finds it necessary to mention the wall at all is - to teach us that the wall of a pit is three Tefachim thick. Consequently, bearing in mind that Shimon too, had to dig his pit three Tefachim from the edge of Reuven's field, Reuven may only dig his pit six Tefachim away from Shimon's.

We need to know this - so that someone who buys a pit together with its walls is entitled to receive a wall three Tefachim thick (see Tosfos DH 'le'Mai'.

Abaye permits Reuven to dig a pit at the edge of his field where it adjoins Shimon's. Rava disagrees on the grounds - that Shimon too, might decide to dig a pit in his field.

Their Machlokes is confined to a field which is not meant for pits, because if it was (such as a Beis ha'Shalachim, which needs to be watered manually), Abaye would concede that it is forbidden.

In the second Lashon, they argue over a field which is meant for pits, because if it was not - Rava would concede that it is permitted.

Abaye permits placing his pit beside the border even according to the Rabbanan, who obligate someone planting a tree to leave a space of at least twenty-five Amos between his tree and his neighbor's pit - because that is only because the pit was there first, whereas in the current case, when Reuven came to dig his pit, Shimon had not yet dug one.

Whereas Rava forbids it even according to Rebbi Yossi, who permits planting it right up to the pit - because there, at the time that he plants the tree, he is not causing any damage to the pit (since it is the subsequent growth of the roots that damage the pit); whereas in our case, every time Reuven pushes his spade into the earth to dig his pit, he weakens the wall of Shimon's (potential) pit.

We learned in our Mishnah that Reuven may not dig a pit beside Shimon's, implying that had there been no pit there, it would have been permitted. According to the second Lashon, where Rava argues with Abaye in the case of a field that is meant for pits - he will establish the Mishnah by a field which is not.

According to the first Lashon, the Kashya is on Rava - who forbids Reuven to dig a pit next to the border with Shimon's field, even when there is no pit in Shimon's field (so why does the Tana permit it here)?

To answer the Kashya, Rava cites what Abaye (or Rav Yehudah) said earlier 'mi'Kosel Boro Lamadnu' - in which case, whoever digs a pit first automatically leaves three Tefachim as the wall of his pit (as we explained there).

Another Lashon cites our Mishnah 'Lo Yachpor Adam Bor Samuch le'Boro shel Chavero', together with Abaye (or Rav Yehudah)'s qualifier 'mi'Kosel Boro Lamadnu'. There is no problem with Abaye according to the Lashon that establishes the Machlokes Abaye and Rava by a field which is not meant for pits - because he will simply establish our Mishnah by a field which is.

According to the Lashon that establishes the Machlokes by a field which is meant for pits, Abaye will establish our Mishnah - where they both come to dig simultaneously, because it is only then that both are required to begin digging three Tefachim away from the border.

The Beraisa discusses a Sela ha'Ba be'Yadayim - soft ground that one can dig with one's hands.

The Tana rules - that if Reuven and Shimon want to dig a pit near the border, each one must move back three Tefachim and dig, and each one must cement his pit.

Assuming that the Tana is speaking where each one comes to dig independently (see Tosfos DH 'Hachi Garsinan'), Abaye will explain that the Beraisa refers to 'Sela ha'Ba be'Yadayim' exclusively, because the earth is soft (but in a case of regular earth, the first person who digs is permitted to dig right up to the border [at least, in a field that was not meant for pits]).

The reason that we asked the Kashya in the first place was - because we thought that although the Tana is speaking about any field, he presents the case of 'Sela he'Ba be'Yadayim', to teach us that, even there, three Tefachim will suffice.