Homer, The Iliad. Trans. Peter V. Jones (New York: Penguin Books, 2003), X.230-240:
Agamemnon lord of men now addressed them:
Diomedes son of Tydeus, my pride and joy, pick the companion you want, the very best of the volunteers. There are plenty of them. Don’t let undue deference make you leave the better man and take the worse out of respect for his birth, not even if he is of higher rank.