Reference for Eruvin 114:15

<big><strong>מתני׳</strong></big> אין מודדין אלא בחבל של נ' אמה לא פחות ולא יותר ולא ימדוד אלא כנגד לבו

- The other thereupon went out and showed him the flanks of a wall that projected seventy and two thirds<span class="x" onmousemove="('comment',' Lit.,'remnants.');">³⁴</span> cubits across the Tigris.<span class="x" onmousemove="('comment',' And thus reduced the gap between the buildings of the two towns to less than a hundred and forty one and a third cubits.');">³⁵</span> <big><b>MISHNAH: </b></big>SABBATH LIMITS MAY BE MEASURED ONLY WITH A ROPE OF THE LENGTH OF FIFTY CUBITS NEITHER LESS NOR MORE;<span class="x" onmousemove="('comment',' The reason follows in the GEMARA:');">³⁶</span>

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