Industries include every profession that the servants (of God) learn or teach others, such as writing, mathematics, trade, gold smithery, saddlery, building, weaving, bleaching, dressmaking, the different sorts of picturing except picturing soulful creatures, and manufacturing the various instruments that people need and benefit. Doing, teaching, and working in all these varieties of industries are legal even if some instruments are used for corruption, acts of disobedience, and support for the wrong against the right, such as writing which may be used for supporting and backing the unjust rulers.
The same thing can be said about knives, swords, and the like tools that are used for both good and evil. Hence, it is not unacceptable to learn, teach, take wages, and work in the good side of such industries. Likewise, it is forbidden to use these industries in evil and harmful ways. In this case, neither the master nor will the student be considered as sinful for using such industries in evil. The guilty will be those who misuse such industries.
God has forbidden only the industries that are wholly illegal and that are harmful, such as the manufacturing of musical instruments, chess, every instrument of illegal amusement, crosses, statues, and the like industries in addition to the industries of forbidden drinks and those that produce illegal things purely without benefiting by any part of them. It is forbidden to teach, learn, work, and take wages for engaging in such industries as well as to manage any part of such industries.