Reference for Bava Metzia 60:9

אלא רבי ישמעאל ברבי יוסי לכולי עלמא אפקרינהו ובמלתא בעלמא הוא דאוקמיה

<b><i>GEMARA</i></b>. And all these that were mentioned already — are they then not lost property?<span class="x" onmousemove="('comment',' The article mentioned in the previous Mishnahs were all examples of lost property; why then state here 'WHAT IS LOST PROPERTY? as though the previous ones were not? ');">²¹</span> — Said Rab Judah: It means this: What is the general principle of lost property for which one is responsible?<span class="x" onmousemove="('comment',' I.e., how may one recognise whether a particular article is lost or intentionally placed there by its owner? ');">²²</span> IF ONE FINDS AN ASS OR A COW FEEDING BY THE WAY, THAT IS NOT CONSIDERED LOST PROPERTY, and he bears no responsibility toward it: [BUT IF HE FINDS] AN ASS WITH ITS TRAPPINGS OVERTURNED, OR A COW RUNNING AMONG THE VINEYARDS, THEY ARE CONSIDERED LOST, and he is bound [to return it]. And for ever?<span class="x" onmousemove="('comment',' Can one say that no matter how long an animal is seen grazing by the way it was intentionally placed there? ');">²³</span>

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