Reference for Pesachim 59:2

ומי אמר רבא הכי והאמר רבא רבי שמעון קנסא קניס הואיל ועבר עליו בבל יראה ובל ימצא

- That is only in its natural state, but not when it is in mixture.<span class="x" onmousemove="('comment',' Even if he kept it in its natural, unmixed state during Passover and then it became mixed with other food, R. Simeon does not penalize him by disqualifying the mixture.');">³</span> Now Raba<span class="x" onmousemove="('comment',' Who accents the ruling of R. Simeon.');">⁴</span>

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