Reference for Yoma 159:4

ואימא ביצת בר יוכני תפסת מרובה לא תפסת תפסת מועט תפסת ואימא ביעתא דציפורתא דזוטר טובא

Whence do we know that the minimum for the ritual uncleanness of foods is the size of an egg? - Said R'Abbahu in the name of R'Eleazar: Scripture says, All food therein which may be eaten,<span class="x" onmousemove="('comment',' Lev. XI, 34.');">⁵</span> i.e., food<span class="x" onmousemove="('comment',' Interpreted: that (coming) from food, which is also eatable.');">⁶</span>

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