Helmut de Boor offers a similarly narrow definition of the nature of morals to be drawn from fables. Opposing "bispel" and fable he sums up the differences as regards this aspect: "The bispel aims at cognition, the fable gives practical knowledge, and in so far as an educational aim is involved the bispel aims at improving man, the fable at making him wiser."
Source: wiktionary
Such episodes and events were used to illustrate and justify more general or abstract 'philosophical' statements in much the same way as exempla or bispel 'edifying illustrative stories' were used in medieval sermons. And just as we have collections of exempla and bispel from medieval times onwards in Europe, [...]
Source: wiktionary
In adopting the bipartite structure, then, the Phoenix-poet demonstrates that this poem is a 'two-fold story,' a bispel.
Source: wiktionary