Salim bin 'Abdullah bin 'Umar سالم بن عبد الله بن عمر بن الخطاب · The Book on Business

"The lawful is clear and the unlawful is clear, and between that are matters that are doubtful (not clear); many of the people do not know whether it is lawful or unlawful. So whoever leaves it to protect his religion and his honor, then he will be safe, and whoever falls into something from them, then he soon will have fallen into the unlawful. Just like if someone grazes (his animals) around a sanctuary, he would soon wind up in…