1 Corinthians 5:6

4 When you are assembled in the name of our Lord Jesus and I am with you in spirit, along with the power of the Lord Jesus,

5 hand this man over to Satan for the destruction of the flesh, so that his spirit may be saved on the Day of the Lord.

Your boasting is not good. Do you not know that a little leaven works through the whole batch of dough?

7 Get rid of the old leaven, that you may be a new unleavened batch, as you really are. For Christ, our Passover lamb, has been sacrificed.

8 Therefore let us keep the feast, not with the old bread, leavened with malice and wickedness, but with the unleavened bread of sincerity and of truth.

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB
Your boasting is not good. Do you not know that a little leaven works through the whole batch of dough?
KJV
Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump?
WEB
Your boasting is not good. Don’t you know that a little yeast leavens the whole lump?
ASV
Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump?
DARBY
Your boasting [is] not good. Do ye not know that a little leaven leavens the whole lump?
BLB
Your⁺ boasting [is] not good. Do you⁺ not know that a little leaven leavens the whole lump?
ÅB
Det er ikke smukt det som dere roser dere av. Vet dere ikke at en liten surdeig syrer hele deigen?
OTB
Deres skryt er ikke fordelaktig. Vet dere ikke at en liten surdeig påvirker hele deigen?
B1930
Det er ikke smukt det som I roser eder av. Vet I ikke at en liten surdeig syrer hele deigen?

Study notes (Tyndale)

Original text and word study

Cross references