1)

(a)If the Koreh is less than ten Tefachim high, our Mishnah prescribes digging a trench across the width of the Mavoy. According to Rav Yosef, the trench must extend at least four Tefachim into the Mavoy. What does Abaye say to this?

(b)Why are both Rav Yosef and Abaye more stringent with regard to extending its height than to reducing it? What is the basic difference between the two cases?

1)

(a)Abaye requires a trench - that extends four Amos into the Mavoy to increase the height of the entrance.

(b)In the previous case, where the entrance has a wall (the edge of the Koreh, about which we say [mi'd'Oraysa even above twenty Amos] 'Pi Tikrah Yored ve'Sosem', as we discussed earlier), the trench is required, not to create a wall, only to change the height of the Koreh; whereas, in our current case, where the Koreh is less than ten Tefachim, we are now coming to create a wall d'Oraysa by digging the trench, and the wall must have a Hechsher Mavoy (four Tefachim, according to Rav Yosef, four Amos, according to Abaye).

2)

(a)If one of the side walls of a Mavoy breaks, leaving a gap in the wall, Rebbi Ami and Rebbi Asi rule that a gap of up to ten Amos does not invalidate the Mavoy - provided that even a makeshift wall (consisting of a plank) of four Tefachim remains still standing at the corner, adjacent to the Koreh that is Matir the Mavoy. Is it correct to say that Abaye (who requires four Amos in the above case) does not hold like Rebbi Ami and Rebbi Asi?

(b)What size breach will invalidate the Mavoy, according to Rebbi Ami and Rebbi Asi, if less than four Tefachim remain at the corner?

(c)Why would the Mavoy be Pasul in this latter case?

2)

(a)It is possible that Abaye holds like Rebbi Ami and Rebbi Asi (who rule that a a wall of four Tefachim adjacent to the entrance permits a breach of up to ten Amos next to it) - because they are speaking about a Mavoy that was formerly Kasher (in which case, if four Tefachim remain, the Mavoy remains Kasher); whereas he is speaking about the initial measurements of a Mavoy (which is four Amos).

(b)If the remaining wall of at least four Tefachim is not there - then a breach of three Tefachim will invalidate the Mavoy.

(c)This is because by a breach of three Tefachim we no longer say 'Levud', combined with the suspicion that the people of the Mavoy will now use the breach as an entrance (instead of the original one adjacent to it); as a short-cut from the Mavoy to the street; and that is not acceptable, since the breach has no Lechi or Koreh.

3)

(a)Abaye proves that a Mavoy which is less than four Tefachim, cannot be Kasher, from a Beraisa, which describes a Mavoy as having at least two Chatzeros opening into it. What is the minimum number of houses that each Chatzer must consist of, and where must they be situated?

(b)What is a Chatzer called if the houses are at the back?

(c)Why can the Beraisa not be speaking (even by a Mavoy of four Tefachim) when the Chatzer opened into the far end of the Mavoy?

(d)How does Rav Yosef explain this Beraisa?

3)

(a)A Lechi or a Koreh will only permit carrying in a Mavoy - if it has at least two Chatzeros opening into it, and each Chatzer must have the front of at least two houses leading into it.

(b)A Chatzer at the back of the house - was usually used as a wood-store and was called a Rechavah.

(c)The Beraisa cannot be speaking when the Chatzer opened into the far end of the Mavoy - because Rav Nachman has already taught us that the length of a Mavoy must exceed its width; otherwise, it has the Din of a Chatzer (which becomes rectifiable by means of a plank of four Tefachim or of two narrow planks - but not by a Lechi or a Koreh, like a Mavoy). So since we are speaking about a Mavoy whose length is four Amos, we must establish its width at less than that, not more.

(d)Rav Yosef will establish the Beraisa- by a Mavoy of four Amos long, and whose far end is less than four Amos. The Chatzeros are situated on the corners, diagonally across the edge of the Mavoy.

4)

(a)Abaye brings another proof from a statement in the name of Rav Huna, who validates a vertical board that protrudes (from a house) across part of the entrance of the Mavoy (even though it was not placed there deliberately as a Lechi), provided it is less than four Amos. What is Abaye's proof from there?

(b)How does Rav Yosef (in whose opinion, a Mavoy that is four Tefachim long is Kasher) refute this proof?

4)

(a)The reason that Rav Huna invalidates a Lechi of four Amos that extends across the entrance of the Mavoy, is because a plank of four Amos is seen as a Mavoy, and not as a Lechi. Is this not because four Amos constitutes the length of a Mavoy - and not four Tefachim?

(b)Rav Yosef however, refutes this proof - on the grounds that a board of four Tefachim may well be considered the wall of a Mavoy, yet that does not mean that it will lose its status as a Lechi; that happens only when it is four Amos long.

5b----------------------------------------5b

5)

(a)How can Rav Huna say that, if the board that extends from the wall of the Mavoy across the entrance of the Mavoy is four Amos long, it requires another Lechi to permit the Mavoy? Is this not simply a matter of extending the Pasul Lechi? Rav Huna Brei de'Rav Yehoshua gets round this by saying 'de'Metafi Bei O de'Mevatzer Bei. What are the two possible meanings of this statement?

(b)What does Rav Papa hold in this case?

5)

(a)When Rav Huna Brei de'Rav Yehoshua says 'de'Metafi Bei O de'Mevatzer Bei - he meant that the added Lechi was not completely flush against the existing one: it is either higher or lower than the Pasul one, or wider or narrower than it.

(b)According to Rav Papa - the second Lechi is not placed beside the first at all, but beside the opposite wall on the other side of the entrance.

6)

(a)According to Rav Huna Brei de'Rav Yehoshua, the above speaks about a Mavoy that is at least eight Amos wide. What will be the Din by a Mavoy that is less than that?

(b)How does he learn this with a Kal va'Chomer from the Din of a Chatzer?

(c)What similar Kal va'Chomer might we have made from a Chatzer by a Lechi of four Tefachim in the entrance of a Mavoy which is more than eight Amos?

(d)On what grounds do we not, in fact, make such a Kal va'Chomer?

6)

(a)According to Rav Huna Brei de'Rav Yehoshua - a Mavoy that is less than eight Amos wide becomes permitted if the plank stretches across the majority of the entrance, because of 'Omed Merubah al ha'Parutz'.

(b)He learns this from a Kal va'Chomer from Chatzer - which does not become permitted by means of a Lechi or a Koreh (yet it does become permitted through 'Omed Merubah al ha'Parutz'), so a Mavoy, which does become permitted through a Lechi or a Koreh, should certainly be permitted through 'Omed Merubah al ha'Parutz'.

(c)We could learn a similar Kal va'Chomer from a plank of four Tefachim, which permits a Chatzer - even if it is more than eight Amos, so how much more so should we permit a Mavoy of eight Amos by means of a plank of four Tefachim?

(d)The problem with the Lechi of which we are speaking is that it was not placed there in order to serve as a plank, which is why it is not valid as a Lechi. For the same reason, it cannot serve as a plank (a Pas) either.

7)

(a)But a Chatzer has a leniency over a Mavoy: namely, that a breach in the wall of a Chatzer only invalidates the Din of Chatzer if it is at least ten Amos, whereas a similar breach in the wall of a Mavoy invalidates the Mavoy, even if it is only four Amos (according to Rav Huna - four Tefachim) long. In that case, how can Rav Huna Brei de'Rav Yehoshua learn a Kal va'Chomer from Chatzer to be lenient by Mavoy?

7)

(a)Rav Huna Brei de'Rav Yehoshua learns a leniency by Mavoy from Chatzer; he is not concerned that a breach in a Chatzer only invalidates if it is at least ten Amos, whereas a breach in the wall of a Mavoy invalidates when it is four Amos or even four Tefachim - because, in his personal opinion, a breach in a Mavoy also invalidates only if it is at least ten Amos - like that of a Chatzer.

8)

(a)Why does Rav Ashi consider the Mavoy Kasher even with an entrance that is eight Amos ...

1. ... when the standing wall is longer than the breach?

2. ... when the breach is longer than the standing wall?

3. ... when they are exactly the same size?

8)

(a)Rav Ashi declares the Mavoy Kasher even with an entrance that is eight Amos wide ...

1. ... when the standing plank is longer than the breach - because of 'Omed Merubah al ha'Parutz'.

2. ... when the breach is longer than the standing wall - because then the plank is considered a Lechi

3. ... when they are exactly the same size - because as we just learnt, whether the Omed is more than the Parutz or vice-versa, the Mavoy is Kasher; the only remaining possibility is that perhaps the Omed and the Parutz are the same (in which case it will be forbidden to carry). Since this is a Safek mid'Rabanan (because min ha'Torah, carrying in a Mavoy is permitted), we apply the principle 'Safek de'Divreihem Lehakel'. Nor is it ever certain that they are exactly the same, because of the principle 'I Efshar Letzamtzem'.