Pharisees and Roman Catholic Priests
The point: Do not blindly believe what the preacher says; go home and search the Scriptures daily to verify the truth.
Martin draws a parallel between the scribes and Pharisees, who interpreted the Law for an unlearned populace, and Roman Catholic priests before the Reformation, who interpreted Latin scriptures for a populace that didn't speak Latin, leading to shackled truth and reliance on tradition.
So the only knowledge the great majority of the people had of what the law said and meant was what the Pharisees told them. You have a perfect parallel, and I'm indebted to Dr. Martin Lloyd-Jones' book and the Sermon on the Mount for these thoughts here. And I'll read it to you in a minute.
17:03 - 17:19 Read in full sermon