1. Trimming off the black hair tips of a פרה אדומה

The Gemara concludes that Rav, who ruled like Rebbe Yose ben HaMeshullam, prohibits דבר שאין מתכוין, but permits plucking a bechor’s hair because תולש לאו היינו גוזז. The Gemara objects that Rebbe Yose ben HaMeshullam seems to permit דבר שאין מתכוין, because he said: שתי שערות עיקרן מאדים וראשן משחיר – if a פרה אדומה had two hairs whose roots are red and whose tips are black, he may trim off the black tips with scissors to validate it, ואינו חושש – and he need not be concerned about violating the prohibition against shearing a bechor. Since he permits an act of shearing if his intent is not for shearing (but to validate the פרה אדומה), he must hold דבר שאין מתכוין is permitted!? The Gemara answers that פרה אדומה is קדשי בדק הבית (i.e., monetary kedushah), which is only Rabbinically prohibited to shear, and פרה אדומה is לא שכיחא – uncommon, and was not included in the decree. Alternatively, the Gemara answers that although Rav holds דבר שאין מתכוין is forbidden, Rebbe Yose ben HaMeshullam himself holds דבר שאין מתכוין is permitted, and for this reason permits trimming a פרה אדומה’s black hair tips.

1. Hair of a בכור בעל מום which fell out, and the bechor was then shechted, or died

In the next Mishnah, Rebbe Yehudah says: שער בכור בעל מום שנשר – regarding hair of a blemished bechor which fell out, and one put it aside, and then shechted the bechor, עקביא בן מהללאל permits the hair for benefit, but the Chochomim forbid it. Rebbe Yose disagrees with Rebbe Yehudah, and says the machlokes is only where the bechor subsequently died. The Gemara explains that where the bechor was shechted, Rebbe Yose holds that all agree the hair becomes permitted. Reish Lakish says the machlokes between עקביא and the Chochomim is בשהתירו מומחה – where an expert had permitted the bechor as a בעל מום before the hair was detached. The Chochomim hold the hair is Rabbinically prohibited after its shechitah (or death), דלמא אתי לשהוייה – lest [the owner] delay the shechitah in order to allow more hair to fall off (and delaying may lead to shearing or working the bechor). עקביא holds they did not prohibit the hair. However, if a מומחה had not yet permitted the bechor before the hair fell out, all agree the hair is forbidden, since it is not [known to be] blemished, and he might delay sacrificing it.

1. בעלי מומין which became mixed with תמימין (examining the flock)

A Baraisa states: בעלי מומין אוסרין בכל שהוא – blemished [animals] which became mixed with unblemished animals prohibit the entire mixture with any amount, but Rebbe Yose says: יב[ו]קר – it should be examined. Rabbah bar Avuha explains that the case is about shearings of a בכור בעל מום mixed with chullin shearings, and this machlokes parallels the machlokes in our Mishnah. Rebbe Yochanan explains that the case is בשבדק ולא מצא – where he checked the entire flock and did not find any blemished animal. Their machlokes parallels another, where one inspected a field in which טומאת מת was lost and did not find anything. Rebbe Meir rules there that anything which was בחזקת טומאה – in an established tumah state remains with its presumption of tumah עד שיתוודע הטומאה– until the outcome of the tumah becomes known. The Chochomim say that one digs until reaching rock or undug earth, after which we assume the tumah is gone. Here, too, the Tannaim argue whether one may sacrifice the entire flock after inspecting all of them. Alternatively, the Mishnah’s case is where he examined some of the flock and found a בעל מום. The Tannaim argue if we may assume this is the lost בעל מום, and this parallels a similar machlokes regarding a field in which a grave was lost.