My clothes are silent when I walk on the earth
Or rest at home, or ride on the waters.
Sometimes my wings and this lofty air
Lift me high above the houses of men,
And the heavens carry me far and wide
Over the world. My feathered wings
Whistle loudly, singing a shrill
And melodious song when, moving high,
I pass like a soul over land and sea.

Anonymous 8th century riddle.