Matthew 23:3 - Ellicott's Commentary On The Whole Bible

All therefore whatsoever... — Followed, as the words are, by repeated protests against special and grave errors in the teaching of the Pharisees, it is obvious that they must be received with an implied limitation. So far as they really sit in Moses’ seat, and set forth his teaching — as, e.g., the scribe had done whose answer has been just recorded — they were to be followed with all obedience. That which was wanting was the life, without which even the highest maxims of morality became but the common-places of rhetorical declamation. It was one thing to “draw fine pictures of virtue,” and another to bring thought and word and deed into conformity with them.