Upon gracing the party with Her divine presence, She discovered that Kiros had foolishly wasted a sizable portion of Her imbued power by casting identification spells on anything and everything for answers. In effort to prevent further stupidity, She wove Her blessing over the staff so that may he use it as a tool to discern the presence of magic. Because that would be much better than frivolously resorting to his own magic and wasting it!

Her blessing was laid upon it at the conclusion of Kiros’ first excursion to Malakath, and the item presented to him as a gift. Not that it was even initially recognized for the boon it was.

Unsurprising; Her priest had long shown himself unable to discern what was good for him.

Revelations
Ambush at Farreach Woods
To Kiros
To Return to Malakath
Faith Illuminated