16:43 Ask the folk of remembrance if you do not know.
This alludes to the fact that knowledge of the Shariah is to learned and is not correct without an intermediary and teacher. Anyone who fancies that the intermediary is useless in knowledge of the Shariah has no portion of the religion.
In short, know that knowledge is of three sorts: knowledge of the Shariah, knowledge of the Tariqah, and knowledge of the Haqiqah. The Shariah is to be learned, the Tariqah is to be practiced, and the Haqiqah is to be found. Concerning knowledge of the Shariah He says, "Ask the folk of remembrance." Concerning knowledge of the Tariqah He says, "Seek the means of approach to Him" [5:35]. Concerning knowledge of the Haqiqah He says, "We taught him knowledge from Us" [18:65]. He turned knowledge of the Shariah over to a teacher, He turned knowledge of the Tariqah over to a pir, and He turned knowledge of the Haqiqah over to Himself.
When someone obtains these three knowledges, a light shines in his heart through which he recognizes the essence of prophethood. When he is given this recognition, he finds this eminence and special favor from the threshold of prophethood: "The men of knowledge are the heirs to the prophets."