At The Supermarket

On a wintry day, my 90-year-old father was in the supermarket trying to pay for his groceries. Bundled up against the cold, his gloved hands were having trouble retrieving and counting the exact change.
The transaction evidently took too long for the man behind him in line, who muttered a curse.
Dad stopped counting, turned around, and warned, “Be quiet or I'll write a check.”