Matthew 16:10-12

Young's Literal Translation

¹⁰ nor the seven loaves of the four thousand, and how many baskets ye took up?

¹¹ how do ye not understand that I did not speak to you of bread -- to take heed of the leaven of the Pharisees and Sadducees?'

¹² Then they understood that he did not say to take heed of the leaven of the bread, but of the teaching, of the Pharisees and Sadducees.