Reference for Eruvin 178:3

והא א"ר אלעזר כי הוינן בבבל הוה אמרינן בי רב משמיה דרב אמרו אין מטלטלין בו אלא בד' אמות והני דבי שמואל תנו אין להן אלא גגן

But, surely, R'Eleazar related, 'when we were in Babylon we used to teach as follows:<span class="x" onmousemove="('comment',' Lit., 'we were saying'.');">⁶</span> The School of Rab in the name of Rab ruled: Objects on a roof<span class="x" onmousemove="('comment',' Lit., in it .');">⁷</span> may be moved only within four cubits, whereas those of the school of Samuel learned,<span class="x" onmousemove="('comment',' A Baraitha.');">⁸</span>

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