1)

(a)We learned in a Beraisa that for the first three days after a person has declared his field Hefker, he is able to retract - even if someone else acquired it first.

(b)Chazal instituted the basic Takanah of being able to retract (verbally) from Hefker - because people were declaring their fields Hefker and then re-acquiring them, with the sole aim of becoming exempt from Ma'aser (and although genuine Hefker is exempt from Ma'aser - that will not be the case if one re-acquires it [as that negates the Hefker]).

(c)And they extended this ruling even to where someone else has already acquired the field (when the reason for the Takanah no longer applies) - because otherwise, the owners would not take it seriously. If others can acquire the Hefker, they will argue, why shouldn't they.

(d)They limited the decree to three days - because one can assume that if he was merely trying to cheat, he would not leave it as long as that before re-acquiring it (in which case his Hefker must have been sincere).

2)

(a)The Seifa of the Beraisa rules that, in a case where the owner declared his field Hefker for a day, a week, a month, a year or a cycle of seven years - the owner can retract (even after three days), provided neither he nor anyone else has acquired the field in the meantime.

(b)Initially, we establish the Reisha like the Rabanan, and the Seifa, like Rebbi Yosi' - who, we currently maintain, forbids the Mudar to benefit from the food that the Madir declared Hefker in our Mishnah because Hefker, like Matanah, does not leave the owner's domain until someone acquires it (like Rebbi Yochanan, explained above), despite the fact that this opinion has already been refuted.

(c)In the Reisha - Rebbi Yosi disagrees with the Rabanan's limit of three days. According to him, the owner would be able to retract even after three days, seeing as the article has not left the his domain.

(d)And in the Seifa - the Rabanan disagree with Rebbi Yosi's concession to retract even after three days. According to them, the owner should not be able to retract after three days have passed, irrespective of whether someone else has acquired it or not.

3)

(a)Despite the fact that, according to Rebbi Yosi, the owner can retract even in a case of Hefker which is not limited to any specific time, he nevertheless restricted his case to when it is - because otherwise, the Din of not being able to retract after someone acquired it, within three days, would not apply (because of the Takanah negating the Hefker, with which Rebbi Yosi agrees in principle).

(b)The ramifications of the statement of Rebbi Yosi that, even if he himself acquires it from Hefker, he can no longer retract are - that the field remains exempt from Ma'aser.

(c)In spite of the fact that the field remains in his domain until someone else acquires it, he is not obligated to Ma'aser the produce - because, the mere fact that someone else may acquire the field indicates that although the field remains in the owner's domain, it is not really his.

(d)Ula and Resh Lakish disagree with this explanation, despite the fact that everything fits so nicely into place - because it is a Dochek (pushed) to establish two parts of one Beraisa according to two different Tana'im.

4)

(a)According to Ula, the author of the entire Beraisa is the Rabanan. And the reason that in the Seifa, the owner can retract even after three days is - because, seeing as it is most unusual to declare a field Hefker for a specific period, the Rabanan agree there with Rebbi Yosi (that the owner retains ownership of the field until someone actually acquires it). This is based on the assumption that this is what he intented when he declared his field Hefker.

5)

(a)According to Resh Lakish, the author of the entire Beraisa is Rebbi Yosi, and the reason that, in the Reisha, Chazal withdrew the owner's right to retract after three days is - because they wanted the field to leave his jurisdiction completely, so that people should realize that the field is not a gift (in which case it is subject to T'rumos and Ma'asros, in which case they would be permitted to separate from crops that are Chayav Ma'asros to cover it, or from it to cover crops that are Chayav), but Hefker, which is Patur.

(b)They did not extend the decree for the first three days - because of the Takanah (on account of people who would declare their fields Hefker only in order to exempt them from Ma'aser, a decree which does not apply after three days - as we explained above).

(c)What prompted the Rabanan to issue such a decree - was the fear that people might think that, since the owner was able to retract before they acquired the field, it is not from Hefker that they acquired it, but from the owner. Consequently, they will treat it as if it was Chayav Ma'asros, separating from it to cover other crops that are Chayav, and vice-versa.

6)

(a)In the previous case, even after the three days, seeing as the owner is able to retract, according to Din Torah, it turns out that the field is not really Hefker at all. Nevertheless - the Chiyuv T'rumos and Ma'asros remains, because Chazal do not have the right to exempt the owner from the Torah obligation.

(b)The problem that this causes is - that the person who acquires it will then think that it must really be Hefker (min ha'Torah) after all, because otherwise, why would Chazal permit him to keep it. As a result of which he will consider the Chiyuv T'rumos and Ma'asros only mi'de'Rabanan, and will proceed to Ma'aser from it to cover other Chiyuvim d'Rabanan (such as crops that have grown in a pot without a hole) and vice-versa.

(c)To circumvent this problem - when Chazal proclaimed the obligation on whoever acquires the field to Ma'aser it, they added the clause that he should confine Ma'asering the crops of that particular field to cover themselves (not to cover any other crops, and not to Ma'aser any other crops to cover them).

7)

(a)The Beraisa discusses the Din of someone who declares his field Hefker regarding Peret, Olelos, Shichechah, Pe'ah and Ma'asros.

1. 'Peret' - is the odd grapes in the vineyard that have fallen on the ground, and that (like Leket in the field), the owner is obligated to leave for the poor.

2. 'Olelos' - is the incomplete clusters of grapes, which one is obligated to leave on the vines for the poor.

(b)Someone who declares his field Hefker - is not obligated to leave Peret and Olelos in his vineyard and Shichechah and Pe'ah in his field, or to separate Ma'asros.

(c)And he remains Patur from separating Ma'asros after he re-acquires it.

(d)He is nevertheless obligated to leave Peret, Olelos, Shichechah and Pe'ah - because the Torah in Kedoshim writes an extra 'Ta'azov' to teach us this.

8)

(a)Ula (who learned above that, according to the Rabanan, within three days of declaring one's field Hefker, the owner may retract) - explains that the above Beraisa is addressing the Torah law, whereas his ruling is mi'de'Rabanan.

(b)Resh Lakish established the Beraisa above (which authorized the owner to retract within three days) like Rebbi Yosi. The owner will nevertheless be exempt from Ma'asros should he re-acquire his field within three days - provided he re-acquires it from Hefker (i.e. without retracting from the Hefker).

(c)Bearing in mind that the Tana of the Beraisa does not require the owner to specify that he is acquiring the field from Hefker - Resh Lakish will establish the Beraisa like the Rabanan (who exempt Hefker from Ma'asros in any event), and not like Rebbi Yosi.