Arab-Byzantine type, imitating Heraclius or Constans II. Three imperial figures standing facing / Large M; cross above; THB left, IAD in exergue, mint name in arabic on the right. 20mm, 2.43 grams. Tiberias mint.  Walker, Arab-Byzantine 43ff.

Interesting and scarce.

These coins are among the earliest coins of the first Islamic Caliphate. Before the more familiar anepigraphic types were issued by the Ummayad, the arab conquerors used a slightly modified Byzantine coinage in the conquered Byzantine lands.