For the source text click/tap here: Pesachim 30
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However, some things "never" become batel; they are assur even b'mashehu, that is, even in the smallest amount. The classic example of this is chametz which is assur even in the minutest proportions.
THIS REMINDS ME OF HOMEOPATHY! AND AVOGADRO'S LIMIT...
AND JOBI'MS "THE WATERS OF MARCH"