So he commanded
and the armies gave a deep resounding roar like waves
crashing against a cliff when the South Wind whips it,
bearing down, some craggy headland jutting out to sea –
the waves will never leave it in peace, thrashed by gales
that hit from every quarter, breakers left and right.
– Homer
The Iliad, Book 2, lines 468-473. This epic simile describes how the Achaean soldiers respond to Agamemnon’s call to arms with a roar like waves crashing against a cliff.