A vintage lyre borrowed from Amadhiah in Vimara Village. Mondstadt has a long-standing tradition of poetry and song. Bards from there tend to address their instruments as "Friend" or "Partner." Thus, one of them trusting Amadhiah with the instrument was nothing less than a gesture of intimacy and trust, and its passage into your hands must also be a gesture of faith and acknowledgment.
As Amadhiah puts it, the person who originally gave him this lyre has already disappeared into the forest.