Mark 8:15
So Jesus gave them this warning. "Take care," he said, "beware of the leaven of the Pharisees and the leaven of Herod."
Luke 12:1
Meanwhile the people had gathered in thousands, so that they trod upon one another, when Jesus, addressing himself to his disciples, began by saying to them: "Be on your guard against the leaven--that is, the hypocrisy--of the Pharisees.
Galatians 5:9
A little leaven leavens all the dough.
Matthew 16:6
Presently Jesus said to them: "Take care and be on your guard against the leaven of the Pharisees and Sadducees."
Matthew 16:11-12
How is it that you do not see that I was not speaking about bread? Be on your guard against the leaven of the Pharisees and Sadducees."
Luke 21:34
Be on your guard lest your minds should ever be dulled by debauches or drunkenness or the anxieties of life, and lest 'That Day' should come suddenly upon you, like a snare.
Acts 14:22
Reassuring the minds of the disciples, urging them to remain true to the Faith, and showing that it is only through many troubles that we can enter the Kingdom of God.
1 Corinthians 5:6-8
Your boasting is unseemly. Do not you know that even a little leaven leavens all the dough?
1 Peter 4:2
and so will live the rest of his earthly life guided, not by human passions, but by the will of God.