Psalm 71:9,17-18 KJV

Cast me not off in the time of old age; forsake me not when my strength faileth. [17] O God, thou hast taught me from my youth: and hitherto have I declared thy wondrous works. [18] Now also when I am old and grayheaded, O God, forsake me not; until I have shewed thy strength unto this generation, and thy power to every one that is to come.