Industry sources meaning [duplicate]
In response to Your idea?, how about letter, as in the letter of the law? From M-W:
the letter of the law: exactly what the law says
Your example:
The Pharisee Jews were extremely legalistic. That is to say, they were paying attention to the letter of the religious orders (i.e., the letter of the law) … rather than ...
People often contrast the letter of the law (e.g., of religious orders) to the spirit of the law (e.g., of religious orders).