Charles Ellicott Commentary Matthew 23:3

"all things therefore whatsoever they bid you, [these] do and observe: but do not ye after their works; for they say, and do not." — Matthew 23:3 (ASV)

All therefore whatever... — Since these words are followed by repeated protests against special and grave errors in the teaching of the Pharisees, it is obvious that they must be understood with an implied limitation. Insofar as they truly sit in Moses’ seat and set forth his teaching—as, for example, the scribe had done whose answer was just recorded—they were to be followed with all obedience.

What was lacking was the life, without which even the highest moral principles became mere platitudes of empty rhetoric. It was one thing to “draw fine pictures of virtue” and another to bring thought, word, and deed into conformity with them.