Matthew 15:16

Do ye not yet understand, neither remember the five loaves of the five thousand, and how many baskets ye took up?

But they understood not that saying, and were afraid to ask him.

And he saith unto them, Are ye so without understanding also? Do ye not perceive, that whatsoever thing from without entereth into the man, it cannot defile him;

But they understood not this saying, and it was hid from them, that they perceived it not: and they feared to ask him of that saying.

And he called the multitude, and said unto them, Hear, and understand:

And they understood none of these things: and this saying was hid from them, neither knew they the things which were spoken.

Jesus saith unto them, Have ye understood all these things? They say unto him, Yea, Lord.

Then opened he their understanding, that they might understand the scriptures,

For they considered not the miracle of the loaves: for their heart was hardened.

For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong me...

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?