Hello,
I agree with Ken,
this must surely be of one of the "Ortolan Buntings". In Germany, a bunting with that bill-colour, a bold white eye-ring dominating the head pattern and uniform peachy-sandy underparts is an Ortolan, but different in Iran, where Cretzschmar's Bunting and Grey-necked Bunting has to be considered,too.
I cant help with the ID, but it looks some kind of strange to me. Upperparts seems too grey and too "clean=geometric" streaked (including just visible pale tramlines). And the head pattern with well marked boarders to the ear-coverts seems quite bold, at least an (german) Ortolan would say this.
Well visible step in tertial-edges excludes Grey-necked Bunting according to literature, but a search revealed, that Cretzschmar's Bunting shouldnt breed in Iran. But even after knowing this, the bird looks some kind of unusual for an Ortolan Bunting. Different populations that differs from those in Europe?
Conclusion? I havent experience with Cretzschmar's Bunting and Grey-necked Bunting, therefore I better wait for more comments. Thanks!