The line comes from The Waltons, the American family drama that aired in the 1970s, where the Walton family's nightly goodnights became one of the show's most recognisable rituals. John-Boy, the eldest son, was often the person being wished good night as the household settled down, and the gentle exchange stuck in popular culture long after the series ended. Shared now as a brief audio clip, it survives because the phrase is instantly recognisable even to people who never watched the show, carrying a sense of old-fashioned family warmth in just a few words.