My father narrated to us. He said: Muhammad b. Yahya al-`Attar narrated to us. He said: Ja`far b. Muhammad b. Malik al-Kufi narrated to us from Sa`id b. `Amr from Isma`il b. Bishr b. `ammar. He said: Harun al-Rashid wrote to Abi’l Hasan Musa b. Ja`far :

Exhort me succinctly. So, he wrote to him: There is nothing that you see before your eyes except that it has an exhortation in it.