Talking Talmud

2 mishnayot: 1 - A first-born son receives a double-inheritance from his father's property, though not his mother's property. (Note: The potential modern will complications (which are largely avoidable, but still) would be in Israel, not elsewhere). But improvements to the property after the father's death and other kinds of property would not be counted as a double portion. Nor a woman receiving her ketubah, nor daughters receiving mezonot, nor a yavam. 2 - During a jubilee year (yovel), the land reverts, but there are exceptions -- including the double-portion of the first-born. Note the Gemara's interpretation of this mishnah -- a husband's inheritance of the wife's property may not revert either, or if it does, perhaps he wouldn't be compensated for it. But this inheritance, according to the Gemara, becomes her family's ancestral plot for burial, and not some other land.

2 mishnayot! 1 - Redemption of the first-born son has to be done via the 5 silver coins (not via objects or land or promissory notes). Rabbi Yehudah HaNasi says - Anything but promissory notes would work, which indicates that his view is not the view of the mishnah. 2 - If the father paid the coins at once, that fulfills the obligation, but what if he handed them over one by one, or to several kohanim? Or if the kohen takes the payment and then returns it? Note how wealthy Rabbi Tarfon didn't keep the coins.

On the 5 silver coins for the redemption of the first-born son, and how they were valuated in other currencies. Which meant getting the math exactly right -- as the example of Rav Ashi sending to R. Acha, who was a kohen, and they need to send back and forth to get the currency exactly right. From the money/coins of the pidyon ha-ben -- when the dedicated coinage to the Temple, there was concern that the Hadrianic and Trajan coins would be all mixed up and profaned that money. Then a verse in Ezekiel calmed the sages down, because it was no longer considered to be consecrated. But there's so much gold and silver in the world - how would this restriction help?!

More mishnayot! 1 - If the first-born son dies within 30 days of birth, there's no redemption to pay and the kohen would return any payment that was already made. After 30 days, the father owes the payment. But what about on the 30th day? 2 - If the father dies, the presumption is that the child is or is not redeemed, based on the timing of the death, compared to those 30 days. What about a first-born father who discovers he himself was never redeemed? Which redemption takes precedence? Note the standard roles in dispute of Rav and Shmuel. Plus, the prevalence, or lack thereof of pidunei ha-ben. 3 - On the coins of the redemption themselves, and how they are derived to be Tyrian shekels from verses in the Torah about redemption in the wilderness. Likewise, other flat fee payments.

Two mishnayot! 1 - A woman gives birth to male twins, and it's not known which of them is the first born, the father gives the coins to the kohen, because one of them needs to be redeemed. But what if one of them dies before 30 days? Or after 30 days? Of if the twins are male and female, and you don't know which was born first? What if it's the father who died? Plus, the case of two people with the same name, and how the adjudicate claims against one of them. 2 - If a man has two wives, and each gives birth to a male baby, the father needs to redeem both of them. But what if one dies within 30 days? What if one of the babies is a girl? And what if the father dies? What if there is further confusion, in cases with two fathers, and the need to redeem sons, but then all the permutations kick in again, with greater scope to argue that the person who owes the redemption is the other guy.