From BibleStrength

Catholicism teaches the Scribes and Pharisees were right in their doctrine and teachings, and that their flaw was in not following what they said - a mistaken interpretation of Matthew 23:3 ("All therefore whatsoever they bid you observe, that observe and do; but do not ye after their works: for they say, and do not.").

Pharisaical Doctrine Was Leaven to be Avoided

However, Jesus indeed warned against following the doctrine of the Pharisees, calling it leaven to be avoided:

Wrong Traditions

It was the Jewish Pharisees, the religious leaders, who were condemned for traditions focusing on the external, the flesh, rather than the heart and spirit:

The Flaw of Externalism

They have fallen to the flaw of externalism, focusing on the outside rather than the inside, the heart, spirit, and soul. As God told Samuel over a thousand years before Jesus came, God does not look on the outside as men do, but on the heart.