Matthew 16:12
Then they understood that He did not bid them beware of the leaven of the bread, but of the teaching of the Pharisees and Sadducees.
Matthew 26:26
And, as they were eating, Jesus, taking a loaf and blessing it, broke it, and giving to his disciples, said, "Take, eat, this is My body."
John 6:52-57
The Jews, therefore, were wrangling with one another, saying, "How can This Man give us His flesh to eat?"
1 Corinthians 5:6-8
Your boasting is not good. Know ye not that a little leaven leavens the whole lump?
Galatians 5:9
A little leaven leavens the whole lump.
1 Thessalonians 1:6
And ye became imitators of us and of the Lord, having received the word in much tribulation with joy of the Holy Spirit;