There shall not any man be able to stand before you all the days of your life. As I was with Moses, so I will be with you; I will not fail you, nor forsake you.
During the long years of the divided kingdom, some kings were reprimanded for appointing priests "from all the people."  Why was it wrong?  The Pentateuch has the answer.  Elijah engaged in the contests with the prophets of Baal as opposed to the God Jehovah.  Where was the superiority of Jehovah taught?  In the Pentateuch.  A king murdered Naboth for his refusal to sell his inheritance.  Where did the laws originate that Naboth endeavored to keep?  In the Pentateuch.  Ahaz made a new Altar, and the description and use of it entailed a discussion of the peace-offerings and many other things that could never have been known in those days except for the teachings of the Pentateuch.