1 Corinthians 5:6-8 (Matins, Epistle)

6

Your glorying is not good. Do you not know that a little leaven leavens the whole lump?

7

Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened. For indeed Christ, our Passover, was sacrificed for us.

8

Therefore let us keep the feast, not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.