God forbid that Achilles sees me turning tail,
heading from town and out to open country –
he’ll come after me full tilt and run me down!
and then no way to escape my death, my certain doom –
Achilles is far too strong for any man on earth.
Wait…what if I face him out before the walls?
Surely his body can be pierced by bronze, even his –
he has only one life, and people say he’s mortal:
it’s only the son of Cronus handing him the glory.

– Homer

The Iliad, Book 21, lines 648-656. The gates of Troy are opened to allow the routed Trojans back into the city, and Apollo inspires the Trojan Agenor to stand his ground to prevent the Greeks from entering. In this passage Agenor resolves to face Achilles, saying that he is mortal and can be pierced by bronze, and it is only Zeus who gives him glory.