ONE of the many puzzles of Iranian dialectology is that quite apart from the countless Arabic and otherwise foreign loanwords in Persian, so many Iranian words of the Persian vocabulary are declared to be non-Persian intruders.
The Persian word for 'king', šāh, is not proper Persian, say the comparative grammarians, because the form to be expected in proper Persian would be *šāš; the word for 'town', šahr, which at an early period meant ‘kingdom ', ought to have been *šas; instead of Pers. sang 'stone' one expects *hang; instead of buzurg 'big ' *buhurg; instead of asp ' horse' *as; instead of asmān 'sky' *āhmān; and even instead of Fārsī Persian ' *Pāhlī.
All these words, and very many others conveying the most ordinary meanings, disagree with one or another rule of what is believed to be the phonology of proper Persian, but agree with what little is known, or can be inferred, about Median phonology. They are accordingly declared Median. And they are declared Median, rather than belonging to some other non-Persic language, for instance Avestan, which in respect of the Old Iranian antecedents of these words behaves like Median, because the ancestors of some of them occur in a supposedly non-Persic form already in Old Persian, at a time, about 520 B.C., when the Persians, having not long before taken over from the Medians a vast empire, would be likely to have been influenced by the administrative, as well as generally cultural vocabulary of the Medes.