'Gray headed' in the Bible

You shall rise up before the gray headed, and honor the face of the old man, and fear your God: I am the LORD.

And now, behold, the king walks before you: and I am old and gray headed; and, behold, my sons are with you: and I have walked before you from my childhood unto this day.

With us are both the gray headed and very aged men, much older than your father.

Now also when I am old and gray headed, O God, forsake me not; until I have showed your strength unto this generation, and your power to every one that is to come.