La ilah illa Allah / al-malik al-haqq / Muhammad rasul Allah / Musa (“There is no God but Allah, the true King, Muhammad is the messenger of God, Musa”) // Al-Imam / Abu Ishaq / Amir al-Mu’minin / Barmaki (“Imam Abu Ishaq, Commander of the Faithful, Barmaki”) 10mm, 0.45 grams. Fishman/Todd "The Silver Damma" #CS19.
"Imam Abu Ishaq" in the inscription refers to Abu Ishaq Muhammad ibn Harun al-Rashid, better known as the Abbsid Caliph al-Mu’tasim (833-42 CE). Musa came from the famous Barmakid family which raised its riches and prominence under the Abbasid Caliphs only to suffer a spectacular downfall during the reign of Harun al-Rashid. Musa was the only survivor of the main branch of the family which was decimated by Harun in a bloody episode in the early 800s CE. These coins were unknown just a year or two ago - they were first published in the Fishman/Todd's "The Silver Damma", and sell for 300-500$ (see the recent auctions by Steve Album).