Matthew 13:33 (NASB)
He spoke another parable to them, "The kingdom of heaven is like leaven, which a woman took and hid in three pecks of flour until it was all leavened."
In Matthew Christ likes the kingdom of heaven to leaven but leaven is consistently used as a picture of sin & corruption in the following verses
Matthew 16:6 (NASB)
And Jesus said to them, "Watch out and beware of the leaven of the Pharisees and Sadducees."
1 Corinthians 5:5-7 (NASB)
I have decided to deliver such a one to Satan for the destruction of his flesh, so that his spirit may be saved in the day of the Lord Jesus. Your boasting is not good. Do you not know that a little leaven leavens the whole lump of dough? Clean out the old leaven so that you may be a new lump, just as you are in fact unleavened. For Christ our Passover also has been sacrificed.
Exodus 12:8 (NASB)
They shall eat the flesh that same night, roasted with fire, and they shall eat it with unleavened bread and bitter herbs.
Exodus 34:25 (NASB)
"You shall not offer the blood of My sacrifice with leavened bread, nor is the sacrifice of the Feast of the Passover to be left over until morning.
How can we understand leaven from the above texts