người đầu bạc tiễn kẻ đầu xanh

Etymology
Literally "the silvery-headed one sees off the green-headed one". is used to describe gray hair, which is thought to be silvery or white rather than gray. means "grue" (either green or blue), but is probably related to, which is likely to be derived from the association of "youth" with "green" and "spring", both of which are in turn associated with the element "Wood" (or "Tree", or "Plant"), the element of "freshness" or "vitality", etc. in. Compare.

Phrase

 * 1) "the young perish and the old linger"; an elderly person has/had to suffer the anguish of watching their young loved one die, because they think it should be the other way around