Ἰλιόθι πρὸ
In a very early stage of the Greek language, prepositions were adverbs, and their placement is thus far more flexible in Homeric Greek than in Classical Greek. Here πρὸ is strictly adverbial. It is thought that tmesis, the separation of a prepositional prefix from its verb, ceased to be part of the spoken/written language before the Greek of the Linear B tablets (i.e. the thirteenth century BCE) but remained an important part of epic diction because of its deeply ingrained presence in the formulaic system and the flexibility it offered for the creation of new formulas (Horrocks 1997:201). The ending -θι of Ἰλιόθι is locative, a vestige of the Mycenaean Greek case system (attested in Linear B). (On the whole phrase see Chantraine 1988, GH I §112.)