Clarifying Text: This is the text of Rabeinu Chananel.

Explanation #1: What the Gemara now means is that Rebbi Chiya asked Rav whether his (Rebbi Chiya's) father was still alive, to which Rav replied that his own father was alive (implying that Rebbi Chiya's was not); and likewise by the mother.

Explanation #2: According to the more common text however, when Rebbi Chiya asked Rav whether his father was alive, the latter that his own mother was alive.

He did not want to answer that his father was alive (like he did according to the first explanation), in case Rebbi Chiya errs and thinks he answered according to what he asked him (and that his father was alive), since it it normal to refer to one's grandfather as 'father'

Clarification: And the reason that the Gemara explains that 'Rav was the son of both Rebbi Chiya's brother and of his sister is, in order to explain why Rav answered in the way that he did.

Question (Part 1): How can we proof from this Pasuk that 'Z'rizin Makdimin le'Mitzvos', but not earlier than morning ...

Question (Part 2): Seeing as in Perek Gid ha'Nasheh (Chulin 91. & 91:) Rebbi Avuhu learns from this Pasuk that a Talmid-Chacham should no go out alone at night?

Answer (Part 1): In fact, the Gemara here is actually learning from the Pasuk of the Akeidah, where Avraham would have had no reason too refrain from going out alone at night ...

Reason #1: Either because a Shali'ach of a Mitzvah can come to no grief ...

Reason #2: Or because he was accompanied by his two servants (in which case he had nothing to fear from demons).

Answer (Part 2): Whereas there (in Perek Gid ha'Nasheh), it learns it from the Pasuk "Vayashkem Avraham ba'Boker (in connection with the destruction of S'dom), where it was not a Mitzvah and where he was alone ...

Reason: Because he did not want others to see the destruction of S'dom.

Explanation #1: The reason for this cannot be due to the fact that since the Chametz belongs to him, nobody other than himself is able to nullify it, and that is why he is Chayav to search ...

Refutation: Because if that was the case, why does the Gemara speak specifically about someone who rented the apartment on the fourteenth, seeing as the same argument will hold water if he rented it on the thirteenth?

Explanation #2: Therefore the Ri explains that since it is his Chametz, the obligation to search for Chametz falls due shortly before the renting takes place.

Proof (Part 1): The Gemara now tries to resolve the She'eilah from Mezuzah, where, even though the obligation to fix a Mezuzah fell on the owner before the renting took place, yet the obligation to fix it lies on the renter.

Proof (Part 2): And the rejects the proof on the grounds that 'The onus of fixing a Mezuzah lies on the person who is currently living in the house' - in which case even if the owner were to simply stop living in the house, he would be exempt from Mezuzah, since he no longer lived in the house and did not use it.

Proof (Part 3): Whereas in the case of Chametz, if he did not rent out the house, he would be Chayav to search (even if he stopped living in the house).

Explanation #1: Rashi explains that handing over the keys is a Kinyan.

Refutation (Part 1): The Ri queries this however, from the Gemara in 'Merubeh' (Bava Kama 79.) which rules that 'Renting Karka, like purchasing it, one acquires with 'Kesef, Sh'tar and Chazakah acquires (and not by Mesiras Mifte'ach)?

Refutation (Part 2): And we only say that Mesiras Mifte'ach is effective in that it is as if the owner says to the hirer 'Go, make a Chazakah and acquire!' (but no more).

Explanation (Part 2): The Ri therefore explains that it speaks here where the owner handed over the key, but the hirer has not yet made a Chazakah - and it is the one who has the key at the beginning of the fourteenth who is able to search for Chametz; since how will the one who does not have the key enter the apaprtment in order to search?

Qualification: If however, Reuven hands over the keys to Shimon for safe-keeping, this does not obligate Shimon to search for Chametz on the fourteenth; Only where he intends to make a Chazakah on the house and to acquire it (see also Tosfos Bava Kama 52. DH 'Keivan', and Tosfos Bava Basra 52: DH "Na'al']).

Question: What does the Gemara think? If the house has a Chezkas Baduk, why do the various parties then need to testify that they searched it?

Answer. Explanation #1: The Ri therefore explains that it speaks where the owner is in town, in which case, even though the house has a Chazakah, one would need to ask him whether or, he searched for Chametz. Consequently, their testimony is effective, in that it is no longer necessary to ask the owner.

Implied Question: Then why, by Tevel (in Eruvin 32.), do we rely on the Chezkas Chaver completely, without needing to ask him?

Answer (Part 1): That is because since, in that case, the Chaver sends the recipient some fruit to eat, he probably rectified it, to ensure that the recipient does not sin.

Answer (Part 2): Whereas in the case of searching for Chametz, even if the house was not searched, the sin will not be so stark. Therefore if the owner is in town, one needs to ask him.

Conclusion: And the Gemara concludes that 'If the house is Chezkas Baduk, then the Tana ought to have said (not 'ha'Kol Ne'emanim al ha'Bedikah', but) 'Kol ha'Batim be'Chezkas Bedukin').

Explanation #2: Alternatively, says the Ri, the Gemara thought that it speaks where the various parties claimed that the house was not searched and that they searched it. Because if the house is be'Chezkas Baduk, they ought to be believed with a 'Migu' since they could have remained silent (without claiming that the house was not searched). But if the house does not have a Chezkas Baduk, why should they be believed?

Conclusion: And the Gemara concludes that 'In that case, then the Tana ought to have said (not 'ha'Kol Ne'emanim al ha'Bedikah', but) 'Kol ha'Batim be'Chezkas Bedukin'), in which case it will be obvious that they are believed with a 'Migu'..

Explanation #1: Rashi explains that this is because the Torah writes "Tashbisu", rather than 'Teva'aru', from which we can extrapolate that 'Hashbasah' implies in the heart (and not verbally).

Question #1: The Ri queries this however, in that 'Hashbasah' means actually destroying the Chametz, and not verbal Bitul - as we will learn in the Beraisa in our Sugya (10.) 'Rebbi Akiva says 'It is not necessary (to write the Pasuk "Lo Sishchat ... ", for the La'av of destroying one's Chametz on Erev Yom-Tov, and not on Yom-Tov), since the Torah already states"Tashbisu", and we find that Hav'arah is is an Av Melachah?

Question #2: Furthermore, later in the Sugya (5:) we learn that the Mitzvah of 'Tashbisu' from "Ach", 'Chalak' applies only after six hours, and 'Bitul' after six hours is ineffective?

Explanation #2: Rabeinu Tam therefore explains that min ha'Torah, Bitul alone will suffice, due to the fact that following the Bitul, the Chametz becomes Hefker, and is no longer in one's possession and is therefore permitted to retain, as we will learn later (Ibid.) ' ... but you may see Chametz belonging to others and to Hash-m (i.e. Hekdesh).

Implied Question: And although the Gemara in Nedarim (45.) rules that Hefker must be done in front of three people ...

Answer: Min ha'Torah, that is not necessary.

Implied Question: Even though whatever is 'be'Yadam' (lies in their power to do), women are believed - even if it is min ha'Torah, since there are daily happenings where we believe women and Avadim with regard to Shechitah and Nikur (removing the Cheilev) ...

Proof: And in Perek ha'Madir (Kesuvos 72.) in connection with 'feeding somebody what has not been Ma'asered, the Gemara implies that she is believed with regard to Chalah and Ma'aser ...

Answer: Nevertheless, regarding Bedikas Chametz, even though it is 'be'Yadam', nevertheless, if it were min ha'Torah, we would not believe them, since there is a lot of effort involved, and it requires careful scrutiny ...

Proof: As is evident in the Yerushalmi, which explains that women are 'Atzlaniyos' (naturally lazy).

Implied Question (Part 1): Why is it that regarding Techumin, which is only de'Rabbanan, yet although we believe a woman and an Eved, we do not believe a Katan ...

Implied Question (Part 2): As we learned in a Beraisa in 'Keitzad Me'abrin' (Eruvin 58:) 'Even an Eved and even a Shifchah is believed to say that the 'T'chum Shabbos goes up to here!', but not Ketanim who are worse, seein as it mentions them last in our Sugya ...

Proof: And in the second Perek in Kesuvos (Daf 28. & 28:) the Gemara states that 'These are believed to testify when they are grown-up what they saw when they were still Ketanim ... up to this point we used to go on Shabbos', implying that whilst they are still Ketanim, they are not believed.

Answer: That is because Techumin is not be'Yadam at all; and this is why they are not believed there like they are regarding Bedikas Chametz.

Clarification: It seems to the Rashba that it is speaking on the thirteenth, because on the fourteenth, the onus to examine the house lies on the owner.

Explanation #1: Rashi explains that since one is Chayav to 'destroy' ("Tashbisu") the Chametz on the 'first day' (i.e. Erev Pesach), we can infer that part of it is permitted.

Question #1: The Ri disagrees however, since "Tashbisu" is synonymous with Hav'arah, and the Torah only obligates burning it after it has become forbidden (see Tosfos Rabeinu Peretz).

Question #2: And besides, if 'Yom Rishon' implies that part of the day is permitted, then why do we need "Ach", 'Chalak'?

Explanation #2: According to Rashi's second explanation however, that according to the Gematriyah 'ACh.As' 'Be.TA' (that 'Alef' = 'Ches' and 'Chaf', 'Tzadei' (spelling 'Chatz' (half), there is no problem.

Explanation #3: The Ri therefore explains that the Gemara is learning from the superfluous Lashon (and not from the implication of the word "Tashbisu").

Explanation #4: Moreover, the Torah asks from the fact that the Torah writes "Ach, 'Chalak' (implying that it is forbidden already from midday).

Additional Answer: The Gemara could have answered that the Torah writes "ba'Yom".

Note (Part 1): And even when it answers that the Torah compares 'Hashbasas Se'or' to 'Achilas Chametz', it does not need to cite the Pasuk "Shiv'as Yamim Se'or Lo Yimatzei" ...

Note (Part 2): Since it could have learned everything from the comparison of 'Hashbasas Se'or' to 'Achilas Chametz'.