"Even in our sleep, pain which cannot forget falls drop by drop upon the heart." is a quote attributed to the Greek playwright Aeschylus.
"For Whom the Bell Tolls ", the episode title, is also shared with a novel by Ernest Hemingway. The phrase originates in Meditation 17 by English poet and cleric John Donne
Frank tells his grandson Sean to "cowboy up!" when Sean was hesitant to open up a college admission letter. Tom Selleck has made a number of westerns.