(Mishnah): The 30 Shekalim for a slave, the 50 of a rapist or seducer...

Question: Why does the Mishnah repeat 'they are Maneh Tzuri'?

Answer: This is due to a rapist and Motzi Shem Ra;

In those Parshiyos it does not say 'Shekalim'. One might have thought that Zuzim are given. The Mishnah teaches that this is not so. We learn from places where it says "Shekalim".

(Mishnah): (All can be paid with money or Shaveh Kesef,) except for (half-)Shekalim.

(Beraisa): (Money or Shaveh Kesef can be used for any obligation,) except for (half-)Shekalim, (redemption of) Ma'aser Sheni and Re'ayon (Olas Re'iyah that one must bring on each festival. the same applies to the Shelamim one must bring.)

Regarding Shekalim, a Mishnah teaches that to facilitate bringing Shekalim to Yerushalayim, they may be converted to gold coins (but not gems. Only currency is guaranteed to retain its value);

Regarding Ma'aser Sheni it says "v'Tzarta ha'Kesef b'Yadcha";

(Rav Yosef - Beraisa): Shaveh Kesef (or even a silver nugget) may not be brought to the Azarah to buy Re'ayon, lest it not be worth the required Shi'ur (the Olah and Shelamim must be worth one and two Ma'ah, respectively).

(Mishnah): One may not redeem with slaves, documents, land or Hekdesh;

If Reuven wrote a document to a Kohen saying 'I owe you five Shekalim (for Pidyon ha'Ben)', his son is not redeemed, and he must pay;

Therefore, if the Kohen wants (the Yisrael to keep his money, the only solution is that the Kohen takes it, and then) he may return the money.

If Reuven separated money for Pidyon ha'Ben and it was lost, he has Acharayus (he must give other money to a Kohen). It says "Yihyeh Lach" (a Kohen will receive the money,) and (only then he is redeemed -) "Pado Sifdeh".

(Gemara): Our Mishnah is unlike Rebbi:

(Beraisa - Rebbi): Anything may be given for Pidyon ha'Ben, except for documents.

Question: What is his reason?

Answer: He expounds Ribuy and Mi'ut (inclusions and exclusions):

"U'Fduyav mi'Ben Chodesh" is a Ribuy. "B'Erkecha Kesef Chameshes Shekalim" is a Mi'ut; "Tifdeh" is another Ribuy. We have a Ribuy Mi'ut Ribuy;

The Ribuyim include everything. The Mi'ut excludes just one thing, i.e. documents.

Chachamim expound Klal u'Frat (general terms and specific terms);

"U'Fduyav mi'Ben Chodesh" is a Klal. "B'Erkecha Kesef Chameshes Shekalim" is a Prat; "Tifdeh" is another Klal;

From a Klal u'Frat u'Chlal we learn everything similar to the Prat, in this case Metaltelim with intrinsic value;

This excludes land (it is not movable), slaves (it is equated to land) and documents (they have no intrinsic value).

Question (Ravina): Rebbi expounds Klal u'Frat!

(Beraisa - R. Yosi b'Rebbi Yehudah): "Martze'a" (an awl is used to pierce the ear of a slave). What is the source to include a wood chip, thorn, needle, drill or stylus?

Answer: "V'Lakachta" includes anything that may be taken in the hand.

Rebbi says, just like Martze'a is of metal, any metal Kli may be used.

Question: What do they argue about?

Answer: Rebbi expounds Klal u'Frat, and R. Yosi bar Yehudah expound Ribuy and Mi'ut.

Answer (Mereimar): Indeed, normally Rebbi expounds Klal u'Frat. Here is different, like Tana d'Vei R. Yishmael taught:

(Tana d'Vei R. Yishmael): "Ba'Mayim... ba'Mayim" (teaches about in which bodies of water we may eat fish only with fins and scales). Because the Prat is not between the Kelalim, we do not expound according to Klal u'Frat, rather, according to Ribuy u'Mi'ut;

Chachamim say, when the Prat is not between the Kelalim, we put it between and expound according to Klal u'Frat.

(Mishnah): One may not redeem with Hekdesh.

Question: This is obvious. Hekdesh does not belong to the one who wants to redeem!

Answer: The Mishnah means that also Hekdesh cannot be redeemed with slaves, documents or land.

(Mishnah): If Reuven wrote a document to a Kohen saying 'I owe you five Shekalim', his son is not redeemed, and he must pay.

(Ula): Mid'Oraisa, his son is redeemed when he pays;

Chachamim decreed that he is not redeemed, lest people say that documents may be used to redeem.

(A reciter of Beraisos): His son is redeemed when he pays.

(Rav Nachman): Your Stam (anonymous) Beraisa is like R. Yosi b'Rebbi Yehudah (some say like R. Elazar b'Rebbi Shimon), but Chachamim say that he is not redeemed.

The Halachah is that he is not redeemed.

(Mishnah): Therefore, the Kohen may return the money if he wants.

Our Mishnah teaches like (the Seifa of) the following Beraisa;

(Beraisa): If one gave five Shekalim (in all) to 10 Kohanim at once, he fulfilled the Mitzvah;

If he gave to one after the other, he fulfilled the Mitzvah. (Rambam - he gave to 10 Kohanim; Tzon Kodoshim's text of Rashi, based on Tosefta 6:4 - he gave the coins to one Kohen, one after the other.)

If the Kohen took the money and returned it, the Pidyon is valid;

R. Tarfon used to do so. Chachamim heard, and said 'he fulfilled this law.'

Question: Is this the only law that R. Tarfon fulfilled?!

Correction: Rather, he fulfilled even this law.

R. Chanina used to take the money and return it. Once, he saw a man lingering around after giving the money (to get it back).

R. Chanina: I see that you did not intend to give it. You acted wrongly;

Your son is not redeemed! (I.e. some explain 'if I would return your money, your son would not be redeemed.')

(Mishnah): If Reuven separated money for Pidyon ha'Ben and it was lost, he has Acharayus.

Question: What is the source of this?

Answer #1 (Reish Lakish): We learn from a Gezerah Shavah "Erech-Erech" from Erchin. (Just like there is Acharayus for Erchin, also for Pidyon ha'Ben.)

Answer #2 (R. Yonasan): It says "v'Chol Bechor Banecha Tifdeh v'Lo Yera'u Fanai Reikam." We learn from a Gezerah Shavah "Reikam-Reikam" from Olas Re'iyah (that one must bring on each Regel). Just like there is Acharayus for Olas Re'iyah, also for Pidyon ha'Ben.

Objection (to both of them - Rav Papa): The Mishnah itself gives a (different) source!

Answer #3 (Rav Papa): We learn from "Yihyeh Lach Ach Pado Sifdeh" (like the Mishnah says);

Reish Lakish (and R. Yochanan) explained a previous Mishnah (49a).

(Mishnah): If a Peter Rechem died after 30 days, even if his father had not yet given five Shekalim, he must give now.

Question: What is the source of this?

Answer #1 (Reish Lakish): We learn "Erech-Erech" from Erchin. (Even if the Ne'erach died, the Ma'arich must pay. Likewise, once the father was obligated, death of the son does not exempt him.)

Answer #2 (R. Yonasan): We learn "Reikam-Reikam" from Olas Re'iyah. Just like there is Acharayus for obligatory Olos, also for Pidyon ha'Ben.

(Mishnah): A Bechor receives a double portion of his father's property, but not of his mother's;

(If the value of his father's property increased after death and before dividing the estate), the Bechor does not receive a double portion of the Shevach (increased value);

The double portion applies only to what was Muchzak (owned at the time of death) to his father, but not to what was only Ra'uy (destined to come to him, e.g. a debt or inheritance).