There is a variant reading in Galatians 5:9 fascinating not only for its sense but for its hermeneutic. The reading of the vast majority of manuscripts here is μικρὰ ζύμη ὅλον τὸ φύραμα ζυμοῖ, “A little leaven ferments the whole batch of dough.” The Western text and two church fathers (D* lat, Marcion according to Epiphanius, and Lucifer) instead read μικρὰ ζύμη ὅλον τὸ φύραμα δολοῖ, “A little leaven adulterates the whole batch of dough.” (See also 1 Cor 5:6, where D makes the same change.) On both internal and external grounds the former reading is to be preferred: It is internally coherent, and Western readings by themselves cannot often claim originality. The hermeneutic of the reading, however, bears discussion as it is a clarification of the sense of the original. The original reading ζυμοῖ uses the literal meaning of the verb in a figurative way: The action of yeast rising throughout a batch of dough serves to illustrate the extensive reach of the corrupting teaching which Paul rails against. The reading of the Western text exchanges that figure for the verb δολοῖ, making the implicit meaning of the figure explicit and literal. A reference to adulteration refers directly to the effect of the false teaching upon the Galatians. The short of it is that the variation is an explanation, not just a variation, and a correct one at that.