Rav Oshaya raises an objection from the mishna to Shmuel’s opinion that all agree that one who acts unawares on Shabbat is exempt: Rabbi Shimon Shezuri and Rabbi Shimon say: Rabbi Eliezer and Rabbi Yehoshua did not disagree with regard to a case involving a matter where his lack of knowledge involves items from one category, as in that case they both agree he is liable. Rather, they disagree with regard to a case involving a matter where his lack of knowledge involves items from two categories, as in that case Rabbi Eliezer deems him liable to bring a sin offering, and Rabbi Yehoshua deems him exempt.

Rav Oshaya continues: And with regard to Rabbi Yehuda, about what matter is he saying that they disagree? If you say he maintains that they disagree in a case where one intended to pick grapes and he picked figs, or to pick black ones and he picked white ones, that is problematic. Rav Oshaya explains: Grapes and figs, black ones and white ones, what are they? Aren’t they two categories? If so, this is identical to the opinion of Rabbi Shimon and Rabbi Shimon Shezuri, who say that Rabbi Eliezer and Rabbi Yehoshua disagree specifically with regard to a mistake involving two categories. If so, what is Rabbi Yehuda coming to teach us?

Rav Oshaya concludes: Rather, is it not correct to say that that the difference between them is the halakha concerning one who performs a transgression while acting unawares? As Rabbi Yehuda holds that one who acts unawares when committing a transgression is liable, and Rabbi Shimon and Rabbi Shimon Shezuri hold that one who acts unawares when committing a transgression is exempt. If so, the opinion of Rabbi Yehuda refutes Shmuel’s statement that all agree that one who acts unawares while performing a prohibited labor on Shabbat is exempt.

The Gemara answers: No, this is not a refutation. In fact, everyone agrees that one who acts unawares is exempt. The difference between the opinions involves a case where the picker lost his train of thought. He initially intended to pick one item, then he forgot and thought that he wanted a different item, and subsequently he unwittingly picked the item he had initially intended to pick. And here it is with regard to this matter that they disagree: As Rabbi Shimon Shezuri holds that when the picker forgot his initial train of thought and instead thought he wanted a different fruit, and both fruits are of one category, all agree he is liable if he ends up unwittingly picking the fruit he initially intended to pick.

When do Rabbi Eliezer and Rabbi Yehoshua disagree? They disagree with regard to a case involving two categories, i.e., when the picker forgot his initial thought and instead thought he required a fruit of a different category. By contrast, Rabbi Yehuda holds that there is no difference between a case of one category and a case of two categories: In both cases they disagree, as Rabbi Yehoshua rules he is exempt because his action did not follow his current intention. But in a case where one acts fully unawares, all agree he is exempt.

The Gemara cites another answer: Rava said that the difference between them is with regard to a case where one intended to perform two transgressions in a specific order and he mistakenly performed the second transgression first. According to Rabbi Shimon and Rabbi Shimon Shezuri, Rabbi Eliezer and Rabbi Yehoshua disagree with regard to a situation where one intended to pick two fruits of two different categories and he unwittingly picked them in the reverse order. In such a case Rabbi Yehoshua holds he is exempt. But when he intended to pick two pieces of fruit of the same category and he unwittingly reversed the order, Rabbi Yehoshua agrees he is liable. According to Rabbi Yehuda, whether the case involves one category or two categories, in both instances Rabbi Yehoshua holds that he is exempt.

With regard to Rava’s explanation, the Gemara cites a baraita that supports the claim that if one intended to perform two prohibited labors in one order and mistakenly reversed the order, he is exempt. And it is taught: If someone had before him two long candles that were lit, and he intended to extinguish this one and instead he extinguished that one, or if he intended to light this one and instead he lit that one, he is exempt. But in a case where he intended to light one and then extinguish the other, and instead he drew a breath and blew the flame from one candle to the other, as he accomplished his intention and extinguished one and lit the other, albeit with one breath, he is liable. This indicates that if he had not performed the two acts simultaneously, but in the reverse order, he is exempt.

With regard to the last ruling, the Gemara asks: Isn’t this obvious? Since he accomplished his act as he had intended, he is clearly liable. The Gemara answers that the ruling is necessary, lest you say: He did not actually perform the labors in accordance with his thought, as he wanted to light one initially and ultimately to extinguish the other, but when he performed the action, it might be considered as though he first extinguished one and ultimately lit the other. And therefore one might say he is exempt. Consequently, the baraita teaches us that although he did not perform the lighting first, as he had intended, nevertheless he also did not perform the lighting after the extinguishing, as they occurred simultaneously. Since his action did not entirely contradict his intention, he is liable.

§ The Sages taught in a baraita: One who stokes coals on Shabbat is liable to bring a sin offering. Rabbi Shimon ben Elazar says in the name of Rabbi Eliezer, son of Rabbi Tzadok: He is liable to bring two sin offerings, because he extinguishes the upper coals that are moved to the bottom, due to lack of oxygen, and he ignites the bottom coals as he moves them to the top. The Gemara asks: What are we dealing with here? If it is a case where he intends to extinguish and kindle, what is the reason of the one who exempts him? Rather, it must be that he does not intend to kindle, but only to extinguish. If so, what is the reason of the one who deems him liable to bring two sin offerings?

Rabbi Elazar and Rabbi Ḥanina both say in explanation: The baraita is referring to a case where a blacksmith needed the coals on top and he therefore intended to extinguish the upper coals, and in order to do that he knew he would ignite the bottom ones. The tanna’im disagree with regard to an undesired act of kindling on Shabbat, which is tantamount to a destructive act. As, the first tanna holds that one who produces an undesired or destructive outcome when he performs the labor of kindling is exempt, and Rabbi Eliezer, son of Rabbi Tzadok, says he is liable. And similarly, Rabbi Yoḥanan says: That disagreement was taught with regard to the case of a blacksmith. And Rabbi Yoḥanan says: Until it was taught that the case involves a blacksmith, the reason for this halakha was not revealed.

Ami bar Avin and Rav Ḥananya bar Avin both say another explanation: