From Wiktionary, the free dictionary
Instrumental singular masculine inflection of 𐎺𐏁𐎴 (vašna, “will, favor”).
𐎺𐏁𐎴𐎠 (va-ša-na-a /vašnā/) m
- by the grace of, by the greatness of, by the will of
(please add the primary text of this usage example)- vašnā Auramazdāha adam xšāyaθiya amiy
- by the greatness of Ahuramazdā I am king