Rashi on Leviticus 11:35/רש"י על ויקרא י״א:ל״ה

1תנור וכרים OVEN OR RANGES FOR POTS — These are movable objects, and they are of earthenware, they have an interior and one places the pot over the opening of the hollow space (the cavity); both have their openings on top.

2יתץ SHALL BE BROKEN DOWN — because for an earthenware article there can be no purification by immersion in water.

3וטמאים יהיו לכם AND THEY SHALL BE UNCLEAN TO YOU — In order that you should not say, “I am under a command to break it down”, it therefore states וטמאים יהיו לכם — i. e. if one wishes to let them remain in their state of uncleanness (when they may still be used for חולין) one has the right to do so (Sifra, Shemini, Chapter 10 10). [יתץ therefore means: “should be broken down”, and the following words signify: “but though they are unclean (וטמאים) they may remain with you ‎(יהיו לכם‎)”].