an instructor of the foolish, a teacher of the immature, since in the law you have the very shape of knowledge and truth.
In context
18you know his will, and you can tell what truly matters, because the law has trained you; 19you are sure you are a guide for the blind, a light for those in the dark, 20an instructor of the foolish, a teacher of the immature, since in the law you have the very shape of knowledge and truth. 21Then you who teach others—do you not teach yourself? You preach against stealing—do you steal? 22You say adultery is forbidden—do you commit adultery? You loathe idols—do you rob temples?