A “rabbinic literary form which has analogies in rabbinic texts is the chreia, also called apophthegma or pronouncement story”

Another rabbinic literary form which has analogies in rabbinic texts is the chreia, also called apophthegma or pronouncement story.  The chreia has its origin in Hellenistic rhetoric and was adopted by both Jews and Christians in antiquity.  It consists of  a more or less brief narrative introduction, culminating in a poignant statement by a “wise man”, whether a philosopher, rabbi, Jesus, or desert monk.  The stories served to propagate the teachings and life styles of exceptional sages by juxtaposing their views and behaviors with those of mainstream society.  They had both an ethical and epideictic function: the wise man served as a moral paradigm for his followers and was, at the same time, venerated by his students and sympathizers of later generations.

Catherine Hezser, “Form-Criticism of Rabbinic Literature”, in The New Testament and Rabbinic Literature, eds. Reimund Bieringer, Florentino García Martinez, Didier Pollefeyt and Peter J. Tomson (Leiden & Boston: Brill, 2010), 102.