3. Abu Ali al-Ash’ariy has narrated from Muhammad ibn ‘Abd al-Jabbar from Safwan from ibn Muskan from al-Halabiy who has said the following: “Abu ‘Abd Allah عليه السلام, has said that ’Amir al-Mu’minin, would write to his agents, ‘You must not make Muslims to perform free labor. Whoever of you asks for what is not obligatory, he has committed transgression and you must not give him anything.’ He (‘Amir al-Mu’minin) would write and recommend about farmers good advice, about them and laborers on hire.’”