Reference for Zevachim 105:12

תניא רבי ישמעאל אומר זה וזה יסוד מערבי ר' שמעון בן יוחאי אומר זה וזה יסוד דרומי

Now, was the altar [only] four cubits?<span class="x" onmousemove="('comment',' It was much larger.');">¹⁴</span> - Said R'Adda B'Ahaba: [It means,] And the place of the horns was four [cubits].<span class="x" onmousemove="('comment',' I.e., the horns occupied four cubits of the altar, since each was a cubit in length and breadth.');">¹⁵</span>

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