Reference for Eruvin 116:6

וכי אין חוט המשקולת יורד כנגדו עד כמה אמר אבימי ד' וכן תני רמי בר יחזקאל ד':

IF HE REACHED A HILL HE SPANS IT AND RESUMES HIS MEASURING. Raba explained: This<span class="x" onmousemove="('comment',' That the method of spanning or piercing is allowed.');">¹¹</span> was learnt only in respect of a hill that has a rise of ten handbreadths to a gradient of four cubits,<span class="x" onmousemove="('comment',' V. Rashi a.I.');">¹²</span>

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