Charles Ellicott Commentary Matthew 15:14

"Let them alone: they are blind guides. And if the blind guide the blind, both shall fall into a pit." — Matthew 15:14 (ASV)

They are blind leaders of the blind — It would appear from Romans 2:19 that this phrase was commonly used to describe the ideal of a rabbi's calling. Now they heard it in a new form, which told them that their state was the very reverse of that ideal. And what was worst about it was that their blindness was self-chosen (Matthew 13:15), and that they were still completely unconscious of it, and boasted that they saw (John 9:41).

If the blind lead the blind, both will fall into the ditch — The proverb was probably a familiar one (it is given in Luke 6:39 as part of the Sermon on the Plain), but as it was spoken now, it had the character of a prophecy. We only need to read the Jewish historian’s account of the years preceding the destruction of Jerusalem to see what the “ditch” was toward which teachers and people were both blindly hastening. Bitter sectarianism, wild dreams, baseless hopes, maddened zeal, and the rejection of the truth that alone had power to save them—this was the outcome they were both preparing for themselves, and from which there was no escape.