Comentário sobre Tahorot 4:1

הזורק. ככר לבין המטפחות – there is no difference whether he threw a ritually pure loaf among ritually impure keys, or whether he threw impure keys among the [ritually pure] loaves, and it is not known if the loaf came in contact with/touched the ritually impure keys, the loaf is ritually pure, for the [anonymous] Tanna/teacher of this Mishnah holds that someone who throws is like one who lacks the awareness/knowledge to be interrogated.

Introduction In the cases in this mishnah a clean loaf of bread is thrown among an unclean pile of keys, or an unclean key is thrown among a pile of clean loaves of bread. The question is: are the loaves or loaf made impure.

ר' יהודה אומר ככשר לבין המפתחות טמא – for Rabbi Yehuda holds that a person who throws (whether impure keys or loaves) has awareness/knowledge to be interrogated, and his [status of] doubt makes him ritually impure. However, when he threw [a ritually impure key among the loaves], it (i.e., the loaf) is ritually pure, since the defilement does not come to rest in a place but rather passes over the ritually pure [loaf], its doubt is [presumed to be] ritually pure. But the Halakha is not according to Rabbi Yehuda. And the [ritually pure] loaf and the [ritually impure] keys that our Mishnah uses, the same law applies for all the rest of the things that are thrown, but because it is the practice of people to throw a loaf and keys one to the other, because of that, [the Mishnah] took this [example].

One who throws an unclean object from one place to another: [for instance] a loaf among keys or a key among loaves, [that which was clean remains] clean. According to the first opinion we can assume that the clean loaf did not touch the unclean keys, and therefore it remains pure. According to this opinion it doesn't matter which was thrown and which remained stationary. In either case, the loaf remains pure.

Rabbi Judah says: if a loaf was thrown among keys the former becomes unclean, but if a key was thrown among loaves the latter remain clean. Rabbi Judah holds that in cases where something pure is thrown and we don't know if it became impure, it is deemed impure. This is because the source of impurity is stationary. But in cases where something impure is thrown and we don't know whether it defiled something else, the other thing remains pure for the impurity was moving.