Reference for Bava Kamma 41:6

תרתי הא דקיימא לאגרא הא דלא קיימא לאגרא

R. Sehorah slated that R. Huna quoting Rab had said: He who occupies his neighbour's premises without having any agreement with him is under no legal obligation to pay him rent, for Scripture says, Through emptiness<span class="x" onmousemove="('comment',' The Hebrew word She'iyyah [H] rendered 'emptiness', is taken to be the name of a demon that haunts uninhabitated premises; cf. Rashi a.l. ');">³</span>

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