Frank Morgan originally was cast as "Gramps" until Lionel Barrymore convinced the studio he was physically able to play the role despite his infirmities.
Although he had been wheelchair-bound due to a twice-broken hip, Lionel Barrymore was able to stand at the end of the film, but his walking was simulated with a moving background.
The Geoffrey Chaucer work referred to in the opening is "The Pardoner's Tale", one of his "Canterbury Tales".
The original Broadway production of "On Borrowed Time" by Paul Osborn opened at the Longacre Theater on February 3, 1938, closing in November 1938 after 321 performances. The major players (with their character names) were Dudley Digges (Julian Northrup - Gramps), Frank Conroy (Mr. Brinks), Dorothy Stickney (Nellie - Granny), Jean Adair (Demetria Riffle) and Peter Miner (Pud).
This film and Calling Dr. Kildare (1939) share much of the same cast and crew. The following actors are in both: Lionel Barrymore, Bobs Watson, Nat Pendleton, Barbara Bedford, Phillip Terry, Dorothy Adams, and Howard Hickman. The following crew worked on both as well: Harold S. Bucquet (Director), Cedric Gibbons (Art Director), Edwin B. Willis (Set Decorator), Douglas Shearer (Recording Director), and Leonid Raab (Orchestrator). Both were released in 1939 and, of course, they were both MGM productions.