1. A wooden כלי which contracts tumah (of משקין) from תוכו or גבו

Rabban Gamliel HaZakein said, as the Gemara explains: כל שאין לו תוך בכלי חרס – any earthenware utensil which has no hollow interior (but is flat), כנגדו בכלי שטף אין לו אחורים לחליקה – a comparable wooden utensil does not have a distinct exterior. Thus, נטמא תוכו נטמא גבו – if its inner surface became tamei, its outer surface is also tamei, and vice versa. He expressed this ruling in reference to a כלי חרס to teach that if the wooden utensil does have a hollow תוך, its halachah parallels a כלי חרס's distinction between exterior and interior. The Torah made this distinction only about a כלי חרס; if a wooden כלי contracted tumah מדאורייתא from either תוכו or גבו, the entire כלי is tamei. The above distinction applies to a wooden כלי for טומאת משקין דרבנן – the Rabbinical tumah of liquids: if a כלי’s exterior became tamei through touching משקין, only the exterior is tamei, but its interior remains tahor. If תוכו became tamei, the entire כלי is tamei. They distinguished this tumah, which is מדרבנן, from ordinary tumah of wooden כלים, so people would not mistakenly burn terumah or kodashim because of such tumah.

1. Eye מומין: are there מומין in the white of the eye?

The Mishnah lists מומין in the eye, such as a punctured, notched or split eyelid, a דק – cataract, תבלול – a mixing of the eye, or various growths. The Mishnah defines a "תבלול" as לבן הפוסק בסירא ונכנס בשחור – if the white of the eye breaks through the ring and enters the black. However, שחור נכנס בלבן – if the black enters the white, it is not a מום. This ruling is subject to a machlokes in a Baraisa: Rebbe Meir says that whether the white enters the black or vice versa, it is a מום, but Rebbe Yose says (like our Mishnah) that if the black enters the white, it is not, שאין מומין בלבן – because there are no blemishes in the white of the eye. Rebbe Yose holds that the passuk, "יצא מחלב עינימו" – they go out [to wickedness] from the fat of their eyes, indicates that תרבא דעינא איקרי – [the white] is only called “the fat of the eye,” but not simply “the eye.” Therefore, it is not subject to eye מומין. Rebbe Meir holds that the word "תבלול" impliesדבר המבלבל את העינים – something which mixes the color of the eyes, so mixing in either direction is considered a מום.

1. Determining if water in the eye is permanent through feeding the animal moist and dry hay

The next Mishnah lists permanent white flecks and water in the eye as מומין. The Mishnah details guidelines for determining if the water in the eye is permanent: whether the animal ate both moist and dry hay (i.e., grown in Nissan and Tishrei, respectively) from a rain-watered field, or from an irrigated field, or dry hay and afterwards ate moist hay, and was not healed, אינו מום עד שיאכל הלח ואח"כ היבש – it is not proven to be a permanent blemish unless it first ate moist and afterwards dry hay and was not healed. The Gemara proves from a Baraisa that our Mishnah holds hay from an irrigated field never proves a permanent מום; only hay from a rain-watered field can. The Baraisa says this treatment process is three months. This refers to the moist hay of Adar and half of Nissan, and the dry hay of Elul and half of Tishrei, totaling three months. The Gemara inquires whether the moist hay is given during זמן לח – the time when hay is moist (Adar and Nissan), and the dry hay during the dry time (Elul and Tishrei), or both are given during the moist time.