OTHER TEACHINGS OF MAR ZUTRA BAR TUVYA
(Mar Zutra bar Tuvya citing Rav): If one learns anything from an Amgushi (this will be explained), he is Chayav Misah [bi'Dei Shomayim].
If one knows how to calculate [the times of] Tekufos and Mazalos, but does not do so, others may not talk with (Ben Yehoyada - highly about) him. (Tekufos are solstices (when the sun reaches its northernmost and southernmost extremes) and equinoxes (when the noon sun is directly over the equator); Mazalos refers to the 12 constellations - the constellations have a fixed rotation, the same constellation is the first to 'rise' each night for about 30 consecutive days.)
(Rav or Shmuel): Amgushi [discussed by earlier Chachamim] is a witch;
(The other of Rav and Shmuel): It is a blasphemer [who constantly entices people to serve idolatry].
Conclusion: We must say that Rav holds that it is a blasphemer, for he said that one learns anything from an Amgushi is Chayav Misah;
This cannot refer to a witch - "Lo Silmad La'asos", but it is permitted to learn [witchcraft] in order to understand it and give Halachic rulings about it.
(R. Shimon ben Pazi): It says about one who knows how to calculate Tekufos and Mazalos, but does not, "V'Es Po'al Hash-m Lo Yabitu u'Ma'ase Yadav Lo Ra'u".
(R. Shmuel bar Nachmani): It is a Mitzvah to calculate Tekufos and Mazalos - "U'Shmartem va'Asisem Ki Hi Chachmaschem u'Vinaschem l'Einei ha'Amim" - Tekufos and Mazalos is the Chachmah that can be shown to Nochrim (through them, one can predict the overall weather for the coming year).
HUNTING AND KILLING ON SHABBOS
(Mishnah): Hunting a deer.
(Beraisa): If one hunts a Chilazon and bruises [or presses] it with his hands to extract its blood, he is liable only once.
R. Yehudah is Mechayev twice;
R. Yehudah: Extracting the blood is included in threshing.
Chachamim: It is not.
(Rava): Chachamim hold that threshing applies only to Gidulei Karka (things that grow from the ground).
Question: He should also be liable for killing!
Answer #1 (R. Yochanan): The case is, he bruises it after it died.
Answer #2 (Rava): We can even say that he bruises it while it was alive - he is Mis'asek regarding killing it (he is engaged in something else).
Question: But Abaye and Rava both say that R. Shimon agrees about a Pesik Reisha (it is as if he intended)!
Answer: Here is different, he prefers that it stay alive, for then the blood makes a clearer dye.
Question: Why is one liable for slaughtering?
Answer #1 (Rav): He is liable for dying (the blood colors the skin).
Answer #2 (Shmuel): He is liable for killing.
Question: Does Rav holds that he is liable only for dying, but not for killing?!
Answer: He means, he is liable even for dying.
Rav: If I do not explain myself, later generations will mock my words!
[One is not liable unless he desired the outcome -] he wants the place of slaughter to be bloodstained, so people will see [that it was slaughtered today] and come to buy.
TANNING, SMOOTHING AND MAKEH B'PATISH ON SHABBOS
(Mishnah): Salting and tanning [the hide].
Question: Salting is [a step in] tanning!
Answer (R. Yochanan and Reish Lakish): Indeed, we must delete one of these, and replace it by Sirtut (scratching a line where one wants to cut).
(Rabah bar Rav Huna): If one salted meat, he is liable for tanning.
(Rava): [He is exempt -] tanning does not apply to food.
(Rav Ashi): Even Rabah bar Rav Huna is Mechayev only if he salted [very heavily,] for a journey [so it will last a long time], not if he salted it [normally] for the house, for then one does not salt so heavily to make food as hard as wood.
(Mishnah): Memachek (scraping the skin) and cutting [it into strips].
(Rav Acha bar Chanina): If one scrapes skin against a pillar (Tosfos; Rashi - he smoothes the ground between pillars), he is liable for Memachek.
(R. Chiya bar Aba): If one scrapes the ends of poles [to make them smooth and sharp], he is liable for cutting;
If one smears a bandage on a wound, he is liable for Memachek;
If one smoothes a rock [that was quarried from a mountain], he is liable for Makeh b'Patish.
(R. Shimon ben Kisma): If one makes a picture on a Kli or blows glass, he is liable for Makeh b'Patish.
(Rav Yehudah): If one cuts off excess strands from a curtain, he is liable for Makeh b'Patish;
This is only if he is insistent to remove them.
(Mishnah): Writing two letters.
(Beraisa): If one wrote a big letter in the space needed to write two [normal] letters, he is exempt;
If one erased a letter big enough to write two letters in its place, he is liable;
R. Menachem b'Rebbi Yosi says, this is a stringency of erasing over writing.
(Mishnah): Building,...Makeh b'Patish.
(Rabah and R. Zeira): One who finishes any Melachah is liable for Makeh b'Patish.
(Mishnah): These are 39 Melachos.
'These' teaches unlike R. Eliezer, who is Mechayev [a second Chatas] for a Toldah done with its Av.
This teaches unlike R. Yehudah:
(Beraisa): R. Yehudah also obligates for Shovet (evening the warp threads) and Medakdek (hitting the woof so it will not be too taut);
Chachamim say, Shovet is included in Meisach, and Medakdek is included in weaving.
FOR WHAT ITEMS IS ONE LIABLE FOR HOTZA'AH?
(Mishnah): Another great general rule of Shabbos:
If an item is fitting to store away, if one was Motzi a quantity that people [normally] save, he is Chayav Chatas;
If an item is not fitting to save, or if it was less than a Shi'ur that people save, only one who saves it is liable if he was Motzi it.
(Gemara) Question: What does 'If an item is fitting to store' come to exclude?
Answer #1 (Rav Papa): It excludes Dam Nidah;
Answer #2 (Mar Ukva): It excludes wood from an Asherah (it is despised and forbidden to benefit from it, on account of idolatry).
Rav Papa excludes Dam Nidah - all the more so he excludes Etzei Asherah;
Mar Ukva excludes Etzei Asherah - he would not exclude Dam Nidah, for people save it to feed to a cat.
Rav Papa disagrees - since one [whose blood is fed to a cat] becomes weak, people do not save it.
(R. Yosi bar Chanina): Our Mishnah is unlike R. Shimon - he says that the Shi'urim are for one who saves them (but one who does not save them is always exempt).
(Mishnah): If an item is not fitting to save...
(R. Elazar): Our Mishnah is unlike R. Shimon ben Elazar:
(Beraisa - R. Shimon ben Elazar): The general rule is - if an item is not fitting to save, or if it is less than people save, and Reuven decided to save it, and Shimon was Motzi it, he is liable on account of Reuven's intent.