1 Corinthians 5:6-13
Your glorying is not good. Know you not that a little leaven leavens the whole lump?…
Some brittle gold, having been accidentally melted with a quantity of well-refined and tough gold, was found to have rendered the whole mass brittle with a highly crystalline fracture, and therefore useless for coinage. The impurity causing brittleness in the whole 75,000 ounces was a small fraction of an ounce, probably one three-hundred-thousandth, or less, of the original weight. It will be seen from this that the saying holds good in metallurgy as well as in morals, "A little leaven leaveneth the whole lump," rendering it totally unfit for current uses, until it has been passed through a purifying process.
(I. C. Booth, LL. D.)
Parallel VersesKJV: Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump?