Adam Clarke on Job 15:10

With us are both the gray-headed - One copy of the Chaldee Targum paraphrases the verse thus: "Truly Eliphaz the hoary-headed, and Bildad the long-lived, are among us; and Zophar, who in age surpasseth thy father." It is very likely that Eliphaz refers to himself and his friends in this verse, and not either to the old men of their tribes, or to the masters by whom they themselves were instructed. Eliphaz seems to have been the eldest of these sages; and, therefore, he takes the lead in each part of this dramatic poem.