(Mishnah - R. Meir): If Reuven said 'this (Chulin) animal is Temuras (in place of an) Olah, Temuras Shelamim', it is Temuras Olah (i.e. it is an Olah);

R. Yosi says, if from the start he meant to say both, they both take effect. Since he cannot say them simultaneously, there is no reason to favor his first words.

30b (Abaye): Rabah bar bar Chanah cited R. Yochanan to say that R. Meir and R. Yosi do not argue about whether we follow the first thing said.

(Rav Dimi): I say that they argue (about whether we follow the first thing said).

Bava Basra 86b (Rav and Shmuel): If Reuven sold to Shimon 'a Kor (30 Sa'im, of grain) for 30 (Sela'im)', either can retract until all is measured out;

If he said 'a Kor for 30, each Se'ah for a Sela', after each Se'ah is measured out, neither can retract (the sale of that Se'ah).

105b Rav Yehudah citing Shmuel): Ben Nanas holds that we follow one's final words. Chachamim disagree. (We are unsure which phrase overrides the other.)

Rif (Bava Basra 43a): The teaching of Rav and Shmuel applies only in a Simta (a shoulder of Reshus ha'Rabim), or in the buyer's Reshus with the seller's Kelim. It cannot be Reshus ha'Rabim or the seller's Reshus, for (even) the buyer's Kelim do not acquire there. If it is in the buyer's Reshus, (even) if it is in the seller's Kelim, he acquires once the seller agreed to sell, even without measuring.

Rambam (Hilchos Mechirah 4:7): If Peros were in a Simta or a joint Chatzer (of the buyer and seller), or even if they are in the buyer's Reshus in the seller's Kli, if the seller agreed to sell and started measuring into his own Kli, if he said 'I sell to you a Kor for 30', he can retract even while measuring out the last Se'ah, since the Peros are still in his Keli and the measure was not completed. The seller's Kli does not acquire for the buyer, even in the buyer's Reshus. If he said '(I sell to you) a Kor for 30, each Se'ah for a Sela', he acquires each Se'ah after it is measured out. Since they set a price for each Se'ah, each Se'ah that the seller lifts and pours completes the sale (of that Se'ah), since the Peros are not in the seller's Reshus or the buyer's Reshus (Magihah - perhaps this should say 'Reshus ha'Rabim'). If the Peros were not in the seller's Keli, since they are in the buyer's Reshus, he acquires from when they set the price, even before measuring, like we explained.

Magid Mishneh: The Rambam's law is clearly true, that he can retract. The Meforshim added that Rav and Shmuel's law applies only in the buyer's Kelim in a Simta, or in their joint Chatzer, and all the more so in his (the buyer's) Reshus. In the seller's Keli he does not acquire. Rather, it is the buyer's Keli. When he said 'a Kor for 30', the buyer does not acquire each Se'ah measured, for the seller is adamant not to sell less (than a full Kor). He does not want a partial sale. Before measuring, the Peros were in the seller's Keli (if they are in the buyer's Reshus), or on the ground if they are in a Simta. Rashi, the Rashba, R. Yonah and the Ra'avad hold like this. It seems that the Rif holds like the Rambam, for he says that Rav and Shmuel's law is only when the seller's Keli is in a Simta or a joint Chatzer. If it is in the buyer's Reshus, in the seller's Kelim, he acquires once the seller agreed to sell, even without measuring. However, perhaps he means (that the Peros were in the seller's Keli) before measuring (but the seller measures into the buyer's Kelim, like the other Meforshim who say that the seller's Kelim do not acquire for the buyer). The latter opinion is primary.

Rosh (Bava Basra 5:17): Even though our Mishnah says that he acquires through Meshichah without measuring, here it is different because he specified that he sells a Kor. He revealed that he wanted to conclude the sale only at once, for he needed the money for a full Kor.

Rosh (Bechoros 1:15): If he said 'a Kor for 30, each Se'ah for a Sela', he acquires each Se'ah after it is measured out, for we are unsure which words we follow. Since he is holding the Peros, he acquires.

Shulchan Aruch (CM 200:7): If Peros were in a Simta or a joint Chatzer (of the buyer and seller), or even if they are in the buyer's Reshus in the seller's Kli, if the seller agreed to sell and started measuring into his own Kli, if he said 'I sell to you a Kor for 30', he can retract even while measuring out the last Se'ah, since the Peros are still in his Keli and the measure was not completed. The seller's Kli does not acquire for the buyer, even in the buyer's Reshus.

SMA (15): The Rif, Rambam and Ramah hold that if he poured into the buyer's Kelim in the buyer's Reshus, since both of these favor him, neither can retract even if he said only 'a Kor for 30', even before the measure is filled. He intended that the buyer acquire each amount measured out. This is why the Shulchan Aruch specified 'the seller's Kelim.'

Rema: If he said '(I sell to you) a Kor for 30, each Se'ah for a Sela', he acquires each Se'ah after it is measured out. Since they set a price for each Se'ah, each Se'ah that the seller lifts and pours completes the sale (of that Se'ah), since the Peros are not in the seller's Reshus or Reshus ha'Rabim. If the Peros were not in the seller's Keli, since they are in the buyer's Reshus, he acquires from when they set the price, even before measuring, like we said in Sa'if 3.

Beis Yosef (DH ba'Meh): The Rashbam explains that when he said 'a Kor for 30', he needed the money for the entire Kor. He intended to sell exactly a Kor, not more or less. Therefore, if he did Meshichah, even if he set a price, and even in the buyer's Reshus and in the buyer's Kelim, he does not acquire until the Kor is totally measured out. Measuring is Me'akev because he was adamant not to sell more or less. Therefore, he can retract even after measuring 29 Sa'im, until measuring the last Se'ah. Even if he did Meshichah on the 29 Sa'im, this is not a proper Meshichah, for it is one sale of a Kor, and he does not acquire until he is Moshech all of it. Our Mishnah says that he acquires through Meshichah without measuring. This is when he sold to him the bundle like it is, and measuring is merely to reveal how much he sold. If he was Moshech all 30 Kor before measuring, the Rosh did not say whether or not he acquires. The Tur says that the Rosh holds that he does not acquire. Perhaps he inferred from the fact that the Rosh did not bring the Rif's words.

Beis Yosef (ibid.): The Tur says in the name of the Ramah and the Rif that Rav and Shmuel discuss a Simta, but if he did Hagbahah or is in the buyer's Reshus, he acquired. 'Simta' excludes Reshus ha'Rabim and the seller's Reshus, but the seller's Kelim in the buyer's Reshus is like a Simta. 'In the buyer's Reshus' refers to his total Reshus, i.e. the buyer's Kelim in the buyer's Reshus. The Rambam wrote like the Rif. He explains that both the case of 'a Kor for 30', and 'a Kor for 30, each Se'ah for a Sela' are when he agreed to sell and began measuring into his own Kelim. Even though the Magid Mishneh said that the opinion of Rashi and those like him is primary, we rule like the Rambam, especially since the simple reading of the Rif is like him.

Beis Yosef (DH Kasav Rabbeinu): The Rashba says that if he gave all the money, even if he said 'a Kor for 30', he acquires each amount measured out, up to the money he paid.

Rema: Some say that he acquires each Se'ah after it is measured out only because he is Muchzak. Therefore, if the buyer did not give the money, the buyer can retract.

Beis Yosef (DH v'Ta'ama): We are unsure whether we follow the initial words or the final words. If so, the same applies if he said 'a Se'ah for a Sela, a Kor for 30.' Each Se'ah measured out is acquired; the seller cannot retract, since it is in the buyer's Reshus. Since it is a Safek, we do not take from him. However, the buyer can retract. 'Each Se'ah measured out is acquired' connotes that this favors the buyer. It did not say 'either can retract.' This is why the Ramah says that if he did not pay, he can retract even from what he is holding.' The Rambam holds that the seller's Kelim do not acquire for the buyer in the buyer's Reshus. Why can't the seller retract? We must say that since he measured, it is as if he said 'go acquire', and this helps even in the seller's Kelim in the buyer's Reshus, unlike R. Yonah.

SMA (23): If the buyer did not pay yet, he can retract because he is Muchzak in his money.