The dangerous leaven

    Luke 12:1a In the mean time, when there were gathered together an innumerable multitude of people, insomuch that they trode one upon another,
Mark 8:15 And he charged them, saying, Take heed, beware of the leaven of the Pharisees, and of the leaven of Herod. Matt 16:6 Then Jesus said unto them, Take heed and beware of the leaven of the Pharisees and of the Sadducees. Luke 12:1b he began to say unto his disciples first of all, Beware ye of the leaven of the Pharisees, which is hypocrisy [1].
Mark 8:16 And they reasoned among themselves, saying, It is because we have no bread. Matt 16:7 And they reasoned among themselves, saying, It is because we have taken no bread.
Mark 8:17 And when Jesus knew it, he saith unto them, Why reason ye, because ye have no bread? perceive ye not yet, neither understand? have ye your heart yet hardened? 18 Having eyes, see ye not? and having ears, hear ye not? and do ye not remember? Matt 16:8 Which when Jesus perceived, he said unto them, O ye of little faith, why reason ye among yourselves, because ye have brought no bread?
Mark 8:19 When I brake the five loaves among five thousand, how many baskets full of fragments took ye up? They say unto him, Twelve. Matt 16:9 Do ye not yet understand, neither remember the five loaves of the five thousand, and how many baskets ye took up?
Mark 8:20 And when the seven among four thousand, how many baskets full of fragments took ye up? And they said, Seven. Matt 16:10 Neither the seven loaves of the four thousand, and how many baskets ye took up?
Mark 8:21 And he said unto them, How is it that ye do not understand? Matt 16:11 How is it that ye do not understand that I spake it not to you concerning bread, that ye should beware of the leaven of the Pharisees and of the Sadducees?
       

Matt 16:12 Then understood they how that he bade them not beware of the leaven of bread, but of the doctrine of the Pharisees and of the Sadducees.

Luke 12:13 And one of the company said unto him, Master, speak to my brother, that he divide the inheritance with me. 14 And he said unto him, Man, who made me a judge or a divider over you? 15 And he said unto them, Take heed, and beware of covetousness: for a man's life consisteth not in the abundance of the things which he possesseth.

[1]Contrast Luke's statement that the leaven of the Phairsees is hypocrisy with Matthew's (16:12) statement that leaven is the doctrine of the Pharisees and Sadducees.