As I was shaving in the glass
Across my face there seemed to pass
The frown of yesterday which made
My little child of me afraid.
And something whispered: "Take a view
At what ill temper does to you."

"Day after day in manner grave
You stand before this glass to shave
And can you quite contented be
what what complacent face you see?
I wonder does it cross your mind
Just how you look when you're unkind?"

by Edgar A. Guest (1881-1959), .