Praying As I Grow Older

Lord, let my spiritual fervor grow
and never diminish with age.
Don't let me close the book on Your work,
though this old body turns a new page.
Give me the heart of a Caleb, Lord,
whose hoary head follows you still;
Though my feeble hands shake
and my failing knees quake,
Just help me to walk in Your will.

Oh, to be like Caleb, who at the age of 85, said, "the Lord hath kept me alive ....while the children of Israel wandered in the wilderness; .....As yet I am as strong this day as in the day that Moses sent me (at 40 years);  as my strength was then, even so is my strength now..."
(3 verses later, it is said,  "because he wholly followed the Lord God of Israel.")