Luke 12:1

Meanwhile as the crowd was gathering in its thousands till they trod on one another, he proceeded to say to his disciples first of all, "Be on your guard against the leaven of the Pharisees, which is hypocrisy,

James 3:17

The wisdom from above is first of all pure, then peaceable, forbearing, conciliatory, full of mercy and wholesome fruit, unambiguous, straightforward;

1 Corinthians 5:7-8

Clean out the old dough that you may be a fresh lump. For you are free from the old leaven; Christ our paschal lamb has been sacrificed.

Matthew 16:6-12

Jesus said to them, "See and beware of the leaven of the Pharisees and Sadducees."

Mark 8:15-21

So he cautioned them, "See and beware of the leaven of the Pharisees and the leaven of Herod."

Luke 5:1

Now as the crowd were pressing on him to listen to the word of God, he saw, as he stood beside the lake of Gennesaret,

Luke 5:15

But the news of him spread abroad more and more; large crowds gathered to hear him and to be healed of their complaints,

Luke 6:17

With them he came down the hill and stood on a level spot. There was a great company of his disciples with him, and a large multitude of people from all Judaea, from Jerusalem, and from the coast of Tyre and Sidon, who had come to hear him and to get cured of their diseases.

Luke 11:44

Woe to you! you are like unsuspected tombs; men walk over them unawares."

Luke 12:56

You hypocrites, you know how to decipher the look of earth and sky; how is it you cannot decipher the meaning of this era?

Acts 21:20

They glorified God when they heard it. Then they said to him, "Brother, you see how many thousands of believers there are among the Jews, all of them ardent upholders of the Law.

1 Corinthians 15:3

First and foremost, I passed on to you what I had myself received, namely, that Christ died for our sins as the scriptures had said,

1 Peter 2:1

So off with all malice, all guile and insincerity and envy and slander of every kind!

Treasury of Scripture Knowledge

Summary

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.

Bible References

First

1 Corinthians 15:3
First and foremost, I passed on to you what I had myself received, namely, that Christ died for our sins as the scriptures had said,
James 3:17
The wisdom from above is first of all pure, then peaceable, forbearing, conciliatory, full of mercy and wholesome fruit, unambiguous, straightforward;

Which

Luke 12:56
You hypocrites, you know how to decipher the look of earth and sky; how is it you cannot decipher the meaning of this era?
Luke 11:44
Woe to you! you are like unsuspected tombs; men walk over them unawares."
James 3:17
The wisdom from above is first of all pure, then peaceable, forbearing, conciliatory, full of mercy and wholesome fruit, unambiguous, straightforward;
1 Peter 2:1
So off with all malice, all guile and insincerity and envy and slander of every kind!

General references

Matthew 23:1
Then Jesus spoke to the crowds and to his disciples.
Luke 14:25
There were large crowds travelling with him; so he turned and said to them,
Galatians 5:9
(A morsel of dough will leaven the whole lump.)