A time long ago- maybe in Darius’ Ecbatana, maybe in the bazaars of Tehran around the time Mosaddegh was overthrown- someone made this golden dagger. The classical sources let us see what such gifts could mean.
For who has richer friends to show than the Persian king? Who is there that is known to adorn his friends with more beautiful robes than does the king? Whose gifts are so readily recognized as some of those which the king gives, such as bracelets, necklaces, and horses with gold-studded bridles? For, as everybody knows, no one over there is allowed to have such things except those to whom the king has given them.
I don’t know whether Xenophon was correct about that last point: lots of Persians in sculptures from court or cemeteries in the provinces wear golden bracelets and silver torcs (and in fact, in the sculptures at Persepolis the subjects are giving the king jewellery rather than the other way around). But he knew that gifts were a serious matter.