A striking statement first spoken on a particular occasion may, through repeated application to similar occasions, become a proverb (mathal). The original event supplies a memorable whole situation that speakers later invoke to characterize another situation.
First occasion: the utterance refers to a particular person or incident.
Later occasions: its remembered pattern is applied to situations with a relevant similarity.
The hearer recognizes the established expression and understands the general lesson conveyed by its original scene. A proverb is not defined merely by short length; it is a conventional utterance whose application has spread beyond its initial setting.