Commentary Par V 64-72

Beatrice now adds a sort of corollary to her previous instruction, warning us in indirect address ('Let not mortals take vows lightly') not to make foolish vows that are better broken than kept.  This constitutes a special case; it is clear that we are meant to consider most vows as being both wise and well intentioned.

Jephthah's keeping of his vow is joined with Agamemnon's equally disastrous pledge with regard to Iphigenia.  Dante pairs a scriptural and a pagan source (cf. the similar proceeding at [Par IV 82-83], linking St. Lawrence and Mucius Scaevola) to underline his point.  See Judges (11:30-40) and Cicero (De offic. III.25 -- according to Moore [Moor.1896.1], p. 263).  But see also, as various commentators point out, Virgil (Aen. II.116-117]) and Ovid (Metam. XII.27-38).  Both Jephthah and Agamemnon make unexamined vows that result in the deaths of their daughters.

The reader may remember another family drama with similar result, the death, not of a daughter, but a mother (Eriphyle), killed by her son (Alcmaeon) out of filial piety; seep Par.IV.100-108 andn C.Par.IV.100-108*.