Taharos 6:2 - 6:3

הטמא עומד – a leper stands underneath the tent or underneath the tree.

וטהור עובר – on the path there, it is doubtful if he touched [the impure leper] or didn’t touch, or it is doubtful if the tent overshadowed him or the tree [overshadowed] over both of them and the ritually pure person was defiled, [and] it is doubtful if it didn’t overshadow and he wasn’t defiled. Or the ritually pure person was standing and the leper was passing. Another explanation, as for example, the creeping animal is in the mouth of the weasel or the carrion in the mouth of the dog passed between the ritually pure individuals or the ritually pure individuals passed between them, the Sages declare ritually pure if there is doubt if he touched or a doubt that he didn’t touch, because the defilement doesn’t have a place, as is taught above in the Chapter "הזורק טומאה" /He who throws defilement [Tractate Taharot, Chapter 4, Mishnah 3] (see also Tractate Negaim, Chapter 13, Mishnah 7). But according to this explanation, if he doubtfully overshadowed or doubtfully did not overshadow, it is impossible to establish to this first clause [of the Mishnah] that the impure person is standing and the ritually pure person is passing by, for regarding the defilement of a tent, there is no distinction between whether there is a place for defilement or whether there isn’t place for defilement, as we proved above in the chapter "הזורק טומאה"/He who throws defilement (Tractate Negaim, Chapter 13, Mishnah 7).

טומאה ברה"י וטהרה ברה"ר – as for example, a store that is open to the public domain, it is doubtful whether he entered or whether he didn’t enter.

ר' יהושע מטמא – for he holds that doubtfully in the private domain and many are engaged with him, we follow after the private domain and his manner of doubt is ritually impure. But the Rabbis hold that we follow after the public domain and his manner of doubt is ritually pure. But the Halakha is not according to Rabbi Yehoshua.

עלה לראשו – [he ascended] to the top of the tree, which is considered the private domain.

הכניס ידו לחור שיש בו טומאה – the hole is considered the private domain, and even though the person is standing in the public domain, since he put his hand into the hole, it is like he is standing in the private domain. But although the tree and the hole were not the private domain regarding Sabbath [law], they are the private domain regarding ritual defilement.

חנות שהוא טמא ופתוח לרה"ר – it would the entirety of all of the store is like the defilement that is placed in the public domain, and just as if there was a creeping animal in the public domain, it is doubtful if he touched it, doubtful if he didn’t touch it, his manner of doubt of ritually pure, here also, if he doubtfully entered into this store or doubtfully didn’t enter into it, his manner of doubt is ritually pure. But if there were two stores, one ritually pure and one ritually impure, it is doubtful whether he entered into the impure store or whether he entered into the ritually pure one, his manner of doubt is ritually impure, for it would be him a doubtful defilement in the private domain.