Rashi, Targum Yonasan and Sifri: It is referring to an earthenware vessel which is not subject to Tum'ah via its outside, only via its inside. ¹ Consequently, if its lid is fixed firmly in place, whatever is inside it does not become Tamei in an Ohel ha'Meis.

Rashi (in Shabbos, 95b), Targum Yonasan and Sifri: It implies an earthenware vessel - whose Tum'ah only enters it via the opening, but not via a hole in the side. ¹

Rashi #1, Targum Onkelos and Targum Yonasan: It means 'whose lid is not firmly attached on it'. ¹

Rashi: "Tzamid" is 'the lid', and "Pasil", 'firmly attached '.

Rashi #2 (in Chulin, 25a) and Sifri: "Tzamid" means 'firmly attached' and "Pasil", 'the lid'.

Sifri: "Tzamid" is 'the stopper' (the lid), ¹ and "Pasil", 'the 'string that one ties round it.

Rashi: It implies that if its lid is firmly attached on it, it is Tahor (even from Tum'as Midras, ¹ since the Pasuk is speaking even where he gave the K'li Cheres to his wife to sit on - Shabbos, 84b).

Chulin, 25a: It implies that, if the lid is not firmly attached, the inside is Tamei, but if it is, it does not become Tamei from the outside. ²

Chulin, 25a: It implies that K'lei Cheres exclusively only become Tamei when the lid is not firmly attached ¹ , but all other vessels are Tamei irrespective of whether the lid is firmly attached or not - because they become Tamei from the outside (via touching, but not from the inside - without touching). ²

Sifri: With reference to where the lid is firmly attached, implies that the same earthenware vessel that saves itself from Tum'as Ohel of a Meis, also saves itself from the Tum'as Ohel of a Sheretz (and of all Tum'os). In other words, if a K'li Cheres with its lid shut tight is placed inside an earthenware oven in whih there is a Sheretz, it remains Tahor