תלמוד על כלים 9:6

Not only if they are wet²⁸All the materials which are permitted as insulating material if dry. but even if they were dry and became wet, as these fibers; are these not like dry which became wet²⁹Babli 49a.? Rebbi Joḥanan bar Shila: This implies that one who hides a cauldron³⁰The translation reads אִיירָה (Syriac אִירָא). (איידי “because of” is Babylonian Aramaic). must let it be missing a little lest he take it up and it spills and heats. There, we stated³¹Mishnah Kelim 9:5. The Mishnah states that while the cake itself is not food, any fluid which oozes from it is olive oil subject to all rules of impurity, but dry olive cake is no longer food and impervious to impurity. By analogy, it is permitted to use dry olive cake to store away hot food on the Sabbath.: “The same holds for new olive cake but old one is pure.” What is new and what is old? Rebbi Yose ben Rebbi Abun in the name of Rebbi Joḥanan: New within 12 months, old after 12 months³²Cf. Avodah zarah 2:5 Note 268, Babli Avodah zarah 34a..