Reference for Menachot 54:14

ורבי יהודה לימא קרא פני מאי אל ש"מ אל דוקא ורבנן אל לאו דוקא

As it was taught by a Tanna in the school of R'Eliezer B'Jacob: The verse, Towards the front of the mercy-seat on the east,<span class="x" onmousemove="('comment',' Lev. XVI, 14.');">¹⁶</span> establishes the principle that wherever Scripture says 'the front' it means the east side.

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