כודאי like a case of certain contact with an impure item? Accordingly, any cases of uncertain ritual impurity should be treated like certain impurity.
וממקום שבאת מה סוטה רשות היחיד אף שרץ רשות היחיד The baraita continues: And since the case of sota is the source for the halakha with regard to uncertain ritual impurity, the details of the halakha are also derived from the case of sota. Therefore, from the place that you came from, i.e., from the source, it is derived that just as the prohibition with regard to a sota applies only when the uncertainty arises in the private domain, i.e., when she has secluded herself with the alleged paramour, so too, uncertain contact with the carcass of a creeping animal renders an item impure only if the contact was in the private domain.
ומה סוטה דבר שיש בו דעת לישאל אף שרץ דבר שיש בו דעת לישאל And furthermore, just as a sota is an entity that has awareness in order for her to be asked whether she actually committed adultery, so too, contact with a creeping animal renders an item impure only if it is an entity that has awareness in order for it to be asked, i.e., a person, or an item that may have contracted impurity in a place where a person was present and could have known.
ומכאן אמרו דבר שיש בו דעת לישאל ברשות היחיד ספיקו טמא ברה"ר ספיקו טהור ושאין בו דעת לישאל בין ברה"י בין ברה"ר ספיקו טהור The baraita concludes: And from here the Sages stated that if an entity that has awareness in order for it to be asked may have contracted impurity in the private domain, its uncertain impurity renders it impure; but if it may have contracted impurity in the public domain, its uncertain impurity leaves it pure. And with regard to an entity that lacks awareness in order for it to be asked, whether the uncertainty arose in the private domain or in the public domain, its uncertain impurity is deemed pure, as it is not similar to a sota.
ורבי ישמעאל א"ר עקיבא תרומה ומהדר ליה איהו כהונה The Gemara begins its discussion of the baraita by inquiring about the exchange between Rabbi Yishmael and Rabbi Akiva: And what was the intention of Rabbi Yishmael? Apparently, he commented on a statement of Rabbi Akiva, who said that it is prohibited for a sota to partake of teruma, and he answered him concerning the matter of the woman’s being prohibited to marry into the priesthood, which was not mentioned by Rabbi Akiva at all.
ותו לרבי עקיבא כהונה מנא ליה וכי תימא כהונה לא צריכא קרא And furthermore, from where does Rabbi Akiva derive that it is prohibited for a sota to marry into the priesthood? And if you would say that with regard to her prohibition against marrying into the priesthood a verse is not necessary,