1 Corinthians 5:6-8

Darby Translation

⁶ Your boasting [is] not good. Do ye not know that a little leaven leavens the whole lump?

⁷ Purge out the old leaven, that ye may be a new lump, according as ye are unleavened. For also our passover, Christ, has been sacrificed;

⁸ so that let us celebrate the feast, not with old leaven, nor with leaven of malice and wickedness, but with unleavened [bread] of sincerity and truth.