Iliad line 1.567

I don't understand the "ἄσσον ἰόνθ". The "ἰόνθ" appears to be masculine or neuter and so can't refer to Hera. Does it refer to the mountain itself? Is eimi (go, walking) used for how much surface something stretches over?

μή νύ τοι οὐ χραίσμωσιν ὅσοι θεοί εἰσ’ ἐν Ὀλύμπωι
ἄσσον ἰόνθ’, ὅτε κέν τοι ἀάπτους χεῖρας ἐφείω.”

Here's my translation (not very literary): Truly none of the gods - how many they may be on the Olymp how far that reaches - when I will bring my invincible hands (against you)