"You shall rise up before the aged, and show deference to the old." Our Sages commented: An aged person means one who has acquired wisdom. Beyond the evidence found in Holy Scripture for their interpretation it was the custom of the ancients to call the wise ones among them "elder"…
It seems superfluous to mention examples of honoring elders among the ancient peoples, it being a known fact. I will mention only one of the highest value…In the land of Greece, when an elder would enter the theater or the circus all those seated would rise to honor him. Once, an old bachelor entered and nobody rose or moved for him. When asked how this elder differed from other elders, they replied: He has not yet given birth to one who will rise before us when we, too, will be as he is today.