1 Corinthians 5:6–8

6 Your boasting is not good. Don’t you know that a little leaven* at leavens the whole batch of dough?au 7 Clean out the old leaven so that you may be a new unleavened batch, as indeed you are. For Christ our Passover lambav has been sacrificed.C 8 Therefore, let us observe the feast, not with old leaven or with the leaven of malice and evil,a but with the unleavened bread of sincerity and truth.