Reference for Menachot 107:14

ת"ש בשר זקנה שהיה בו כשיעור וצמק פחות מכשיעור טמא לשעבר וטהור מיכן ולהבא

Rab, R'Hiyya and R'Johanan read: 'according to their present state'; whereas Samuel, R'Simeon B'Rabbi and Resh Lakish read: 'according to their former state'. An objection was raised: If a piece of calf's flesh which was not of the prescribed size<span class="x" onmousemove="('comment',' An egg's bulk.');">¹⁵</span>

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