I pray that I may not judge a man, until I have walked a mile in his moccasins.
~old cherokee saying
The "variation" of this is an unattributed joke that is all over the internet
I have absolutely no confidence that Handy had anything to do with it.
Before you criticize someone, make sure you've walked a mile in their shoes. That way, you're a mile away AND you have their shoes!
http://www.linearconcepts.com/etc/quotes.asp?q=b
"You never really understand a person until you consider things from his point of view-until you climb in his skin and walk around in it."
~Atticus Finch- To Kill a Mockingbird