'Leaven' in the Bible

Another parable spake he unto them; The kingdom of heaven is like unto leaven, which a woman took, and hid in three measures of meal, till the whole was leavened.

Then Jesus said unto them, Take heed and beware of the leaven of the Pharisees and of the Sadducees.

How is it that ye do not understand that I spake it not to you concerning bread, that ye should beware of the leaven of the Pharisees and of the Sadducees?

Then understood they how that he bade them not beware of the leaven of bread, but of the doctrine of the Pharisees and of the Sadducees.

And he charged them, saying, Take heed, beware of the leaven of the Pharisees, and of the leaven of Herod.

In the mean time, when there were gathered together an innumerable multitude of people, insomuch that they trode one upon another, he began to say unto his disciples first of all, Beware ye of the leaven of the Pharisees, which is hypocrisy.

It is like leaven, which a woman took and hid in three measures of meal, till the whole was leavened.

Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump?

Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us:

Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth.

A little leaven leaveneth the whole lump.