I also took a class with Mark Aspery! He taught me to forge and heat treat a 4140 cold chisel and cleaned up my hammer swing! (I was questioning my own memory of his saying this rhyme but only for the last quarter)
"If the Blacksmith will, a keen edge win; he must forge thick, then file thin."
(the only thing I can't 100% remember is if he said "and" instead of "then".) Anyway, this version scans and has a pleasant flow and it's how I remember Mark saying it.
Have a good one brother!
Noah
Cool to learn some history of this pleasant little phrase, thank you brother!