In book 5 of the Iliad, Homer describes the deaths of the twins Krethon and Orsilochos at the hands of Aeneas. After quite a long description of their courage and strength, he describes how they fell. The sound of the word for “fell down” καππεσέτην so well describes the tree falling down that I wonder if Homer inserted the episode just so that he could use this dual form. The double π in the first syllable καππ gives the impression of something about to fall but just teetering before it finally comes down in the subsequent syllables.
τοίω τὼ χείρεσσιν ὑπ᾽ Αἰνείαο δαμέντε
καππεσέτην, ἐλάτῃσιν ἐοικότες ὑψηλῇσι.
These two overcome by the hands of Aeneas fell down like tall fir trees.