In The Name of Allaah, The Most Merciful, The Bestower of Mercy
It was said to Muhammad Ibn Al-Hasan Ash-Shaybaaniy [rahimahullaah]:
“Will you not author a book on Zuhud?” He said: “Indeed, I have written a book on business transactions.”
Shaikh Uthaymeen [rahimahullaah] said: “When it was sought from Muhammad Ibn Al-Hasan [rahimahullaah] to author a book on Zuhud, he said, “Indeed, I have written a book on business transactions”; because whoever is acquainted with business transactions and its [sound Islamic] rulings, he will avoid haraam and declare lawful what is to be declared lawful, and this person is the Zaahid [i.e. a person of abstinence in reality].