The phrase 'Βάκχαις Δελφίσιν' presents a specific textual crux regarding the dative plural forms. While the dative of the noun Βάκκαι (Bacchae) is regularly Βάκχαις, the form Δελφίσιν is a unique poetic contraction or variation of Δελφίσι (from Δελφίς, 'Delphian' or 'Delphic'), where the sigma of the standard dative plural ending -σι(ν) is dropped or assimilated in the metrical context. This construction is not found in standard prose and requires careful attention to the metrical constraints of Aristophanic iambic trimeter versus the Doric or poetic dialectal features often preserved in choral or comic invocations. The epithet 'Delphic' applied to the 'Bacchae' is also semantically complex, as it conflates the Thyiads (Bacchic followers) with the Delphic priestesses or the oracle itself, suggesting a specific allusion to the syncretism of Dionysiac and Apolline worship at Delphi, a theme particularly relevant in the context of the play's critique of Socratic innovation and traditional piety.