How does the joke about asking for a daughter’s hand use literal and metaphorical meanings?

The joke about asking for a daughter’s hand relies on a technique known as "bisociation," where a situation is perceived through two mutually incompatible frames of reference simultaneously.1

In this dialogue, the phrase "ask for your daughter’s hand" is initially presented within a traditional, metaphorical frame of reference, where it serves as a formal, symbolic request for permission to marry. However, the father’s response—"Why not? You have already had the rest"—abruptly shifts the listener to a literal, bodily context. By reinterpreting "hand" as just one part of the daughter's physical body, the joke creates a sudden mental jolt as the listener is forced to reconcile the polite, conventional request with a crude, literal interpretation of the anatomy involved. This clash between the social code of courtship and the literal, physical reality is what produces the comic effect.12