Galatians 5:9

μικρὰ ζύμη κ.τ.λ. Despise not the beginning of evil. I grieve not only for what is but for what will be (cf. Theodore, Chrys.). The proverb is general, but to the Jewish mind ζύμη would suggest at once that which might not be offered to God on the altar (Leviticus 2:11), though permitted when the bread was to be eaten by the priests (Leviticus 7:13). The leaven here is the false doctrine which seemed so slight and harmless (cf. Galatians 5:2-3 notes), not the false teacher (τίς, Galatians 5:7) regarded as one in contrast to many. For this has no point here. In 1 Corinthians 5:6 it is otherwise; the sin of one individual spoils the whole body of Christians at Corinth.