After Issa bin Ali had visited the prisons, he found it was necessary to treat the patients and preserve their humanity so, he sent his famous letter to Sanan in which he said: ''I thought of the imprisoned people and what they are exposed, due to their big number and their hard situation, to diseases; they are incapable to deal with their excretions or to meet doctors to seek their advice about diseases. You have - May God grant you honor - to assign physicians to visit them daily and they should carry with them drugs and syrups and all they need to treat the patients and cure illnesses with God's will ''