Reference for Bava Batra 39:3

והא עשבין חזו לבהמתו באפרזתא

Or if you like I can say that its mouth is turned outwards, and here we are speaking of a jar of metal.<span class="x" onmousemove="('comment',' Which is liable to communicate uncleanness from its outside as well as inside. ');">³</span>

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