Reference for Bava Batra 45:4

<big><strong>גמ׳</strong></big> חמשים אמה ותו לא ורמינהי אין פורסין נשבין ליונים אלא אם כן היה רחוק מן הישוב שלשים ריס

WHICH IS AS MUCH AS A BIRD FLIES AT A TIME. IF, HOWEVER, HE BUYS IT [FROM ANOTHER] WITH ONLY THE SPACE FOR SOWING A QUARTER OF A <i>KAB</i> ROUND IT,<span class="x" onmousemove="('comment',' About 105 square cubits. ');">⁶</span> HE HAS A RIGHT TO KEEP IT.

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