Leviticus 19:32
You shall rise up before the hoary head and honor the face of the old man and [reverently] fear your God. I am the Lord.
Hoary: grey: showing characteristics of age, especially having grey or white hair; "whose beard with age is hoar"
Reverence: regard with feelings of respect and reverence; consider hallowed or exalted or be in awe of; "Fear God as your father"; "We venerate genius"