Explanation: He holds like Rebbi Shimon who says that a relative can testify. The Pasuk, "This month is for you" refers to amongst you (any Jew can testify). We derive that "Kesheirin u'Meyuchasin" excludes a Ger Toshav and a Mamzer, similar to the way we derive in Sanhedrin (36b) that the Pasuk, "with you" refers to those who are similar to you.

Observation: The Gemara implies that all of the people who are unfit to testify in the Mishnah are unfit according to Rabbinic law.

Observation (cont.): This is as we say regarding the Mishnah that a thief according to Rabbinic law may testify regarding a woman (i.e. her ability to remarry).

Observation (cont.): This is understandable regarding a gambler, according to the opinion in Sanhedrin (24b) that he is invalid to testify because he is not settling the world (i.e. making an honest living). (Since it is not really thievery, it is understandable why the Mishnah had to state that he is an invalid witness for the new moon.) According to the opinion that gambling is stealing since Asmachta Lo Kanya (a deal based on each person thinking they are going to win is not valid, and therefore whoever takes the money is deemed to be stealing), the gambler does not consider himself a thief, since the other person knowingly allows this to happen (and is why the Mishnah had to state he is invalid).

Observation (cont.): A person who lends money with interest that is not a set amount, and even if it is a set amount, is not known to be sinning since everyone involved in the loan is doing so willingly, unless the lender forces the borrower to give collateral (and is why the Mishnah had to state he is invalid).

Observation (cont.): Pigeon racers, according to the opinion that this involves whether your pigeon will beat my pigeon in a race, are the same as gamblers. According to the opinion that this involves a person who owns a pigeon that forces other pigeons to come to his coop, this is not outright thievery, and is only forbidden due to maintaining peaceful relations amongst people (and is why the Mishnah had to state he is invalid).

Observation (cont.): People who sell Shemitah produce refers to Shemitah nowadays according to Rebbi who is recorded in Gitin (36a) as saying that Shemitah today is a Rabbinic law. Alternatively, it is regarding someone who deals in Shemitah produce in a way that is only forbidden according to Rabbinic law. For example, the Gemara in Sanhedrin (26a) says regarding people who give money to the poor, and the poor gather Shemitah fruit and give it to them, that this is forbidden according to Rabbinic law. This is not outright dealing in Shemitah produce, as they are just being messengers (and is why the Mishnah had to state he is invalid).

Implied Question: The Gemara in Sukah (39a) implies that it is permitted to sell Shemitah fruit to an Am ha'Aretz when it says that he can include the price of the Esrog in the price of the Lulav (that he sells him for Arba Minim). The Gemara there is concerned about giving money of Shemitah fruit to an Am ha'Aretz. However, it is not concerned about the prohibition of selling Shemitah fruit.

Implied Question (cont.): The Gemara in Sanhedrin (26a) also asks regarding a Sa'ah of Terumah that fell into less than one hundredth of Shemitah produce, "Why don't we sell it to a Kohen for the price of Terumah?" (The Gemara does not seem concerned about the prohibition against selling Terumah.)

Answer #1: If a person gathered Shemitah produce in order to eat it and he has leftover fruit, he is permitted to sell it. He is also allowed pay back his loan with it, as implied in Avodah Zarah (72a) that even though there is a general prohibition implied from the Pasuk, "to eat" regarding Shemitah fruit, implying that one may not do business with it, even so one may use the leftovers to sell or to pay back loans.

Answer #2: It is possible that someone who buys Shemitah fruit in order to eat it is not considered having done business with it unless he buys it cheaply in order to sell it for more money and to make a profit.

Observation: The Rash explains the Mishnah in Shevi'is (8:4) based on the opinion of the Yerushalmi on this topic.

Implied Question: Kenani servants are not stated in Sanhedrin (24b), as they are unfit for testimony according to Torah law. However, our Mishnah needed to state that they are unfit. (Isn't this obvious if they are even unfit according to Torah law?)

Answer: This is in order that you should not say that they are valid for testifying about the new moon, since they are not unfit due to having committed a sin. This would be like relatives being fit according to Rebbi Shimon (even though they may not testify in other matters according to Torah law, they may testify regarding the new moon).

Explanation: The witnesses that saw the new moon, and even the witnesses who testify that they know them when Beis Din does not know that they are credible witnesses, are reason to desecrate Shabbos.

Proof: This is apparent from the beginning of the second chapter where we see that Rebbi Nehorai went to the witness in Usha on Shabbos in order to testify about him.

Observation: This additional person may also have Shabbos desecrated on his behalf for this purpose, as explained earlier at the end of the first chapter.

Question: This is difficult. Even if he is not believed he is allowed to desecrate Shabbos to go there, as perhaps he will be able to testify together with someone else!

Proof: This is as the Mishnah states regarding a father and son that they should both go even though they cannot testify together, as if one of them becomes invalid the second can testify together with someone else.

Answer: It appears that the question is not how he can desecrate Shabbos since he is not believed on his own, but rather that the Mishnah says, "another one" implying that one person is believed.

Question: It is difficult to understand why Rav Papa says this, as I can say that "Oso" refers to one of the two witnesses.

Explanation #1: It is possible to explain that the case was where one witness saw the moon and Rebbi Nehorai went to pair up with him to testify about the new moon as well. When the Beraisa says he was "testifying about him," it is referring to the moon.

Explanation #2: However, in the Yerushalmi and Tosefta it is clearly apparent that Rebbi Nehorai went to testify that the witness was a valid witness. This is also the explanation of Rashi. The question "If so" is regarding both answers.

Explanation: The thirtieth day of Adar fell on Shabbos, and the moon was not seen in its normal time. The Beitusin always want the first day of Pesach to be on Shabbos, so that the Omer will be brought on Sunday and Shevuos will fall on Sunday. This is because they understand the word Shabbos in the Pasuk "from the day after Shabbos" to be referring literally to Shabbos (as opposed to Yom Tov). This is Rashi's explanation.

Question: What do they gain? They will have a problem because Pesach is not going to be on the right day!

Answer: They don't consider (their false testimony in this matter) this a problem, as they do hold of the derivation "you" even if you purposely (make the wrong day Rosh Chodesh it is valid).

Explanation: The Yerushalmi implies that this was in order that they should not mistakenly think the torch is a star, as Rebbi Asi says that we see a star that goes down and then up, a star that goes sideways.

Observation: The Gemara also could have said that this was because of a Rosh Chodesh of a full month that falls on Shabbos for the same reasons.