Cross reference
Matthew 16:11
11 How is it that ye do not perceive that I spake not to you concerning bread? But beware of the leaven of the Pharisees and Sadducees.
Matthew 16:6
6 And Jesus said unto them, Take heed and beware of the leaven of the Pharisees and Sadducees.
Mark 4:40
40 And he said unto them, Why are ye fearful? have ye not yet faith?
Mark 8:21
21 And he said unto them, Do ye not yet understand?
Luke 12:56
56 Ye hypocrites, ye know how to interpret the face of the earth and the heaven; but how is it that ye know not how to interpret this time?
John 8:43
43 Why do ye not understand my speech? `Even' because ye cannot hear my word.