The passage that begins here functions much like an arming scene. In a well-known article, James Armstrong (1958) shows how formulaic arming scenes are employed at climactic moments in the Iliad with great effect. He analyzes in detail the four major arming scenes of the Iliad (those of Paris in Iliad 3, Agamemnon in Iliad 11, Patroklos in Iliad 16, and Achilles in Iliad 19), arguing that formulaic language in these passages is manipulated for various poetic purposes, and that each scene resonates with what came before, so that there is a cumulative effect over the course of the poem.
In the night raid/lohkos tradition, the dressing and arming of heroes would no doubt have had a poetic purpose similar to the expanded arming scenes of conventional battle. These scenes contribute both to suspense, by increasing the audience’s anticipation of the coming ambush or raid, and to characterization, as the details of each dressing or arming passage reveal important aspects of the hero’s character as a fighter. But even more importantly, the passages serve to signal that the poet is moving into a different poetic register. The poet transitions by way of such scenes from one megatheme to another, and the alternative style of clothing is emblematic of not only this alternative mode of fighting but also an alternative poetics.
The armor described here is in many ways atypical. Most distinctive is what the heroes wear on their heads. Diomedes and Odysseus wear leather skull caps (κυνέην … ταυρείην … ἥ τε καταῖτυξ κέκληται—the word καταῖτυξ is used only here in extant Greek literature), and the history of Odysseus’ cap is elaborately described: Odysseus’ own maternal grandfather Autolykos stole it and gave it away as a gift to Amphidamas, who likewise gave it as a gift to Molos, who then gave it to the Cretan Meriones, who now gives it to Odysseus along with the other weapons Odysseus will carry, a bow and quiver and sword. Meriones must give Odysseus all of this gear because when Odysseus leaves his tent, unlike the other heroes who dress in skins and cloaks and take their weapons, he takes only his shield. (See above on 10.149.)
But both heroes, it should be noted, are given weapons and armor by the two leaders of the guards, Meriones and Thrasymedes, who came out into the night fully armed. Diomedes, we are told here, borrows a sword and shield from Thrasymedes, just as Odysseus uses Meriones’ bow, quiver, sword, and helmet. Such borrowing may reflect the impromptu nature of the mission—a quality that will be seen again when it changes from a spying mission to an ambush/night raid. Or it may give the mission a communal aspect, which can also be seen in the rest of the leaders remaining in this same spot, beyond the ditch, until Diomedes and Odysseus return. They are all invested in the success of these two.
But while the clothing they wear and weapons they carry are unusual for extant Homeric epic, they are completely appropriate for a night raid, where, unlike the polemos, it is important not to be conspicuous. (See also Shewan 1911:55.) The history of the cap as a gift indicates that such an object has prestige as well as utility, and possession of it may indicate “the best,” who would wear such equipment for these dangerous and important missions. That it was originally stolen by the thief extraordinaire Autolykos seems related to the stealth that it affords the wearer, and also makes it even more fitting both for Odysseus personally, who is very much like his grandfather, as we know from Odyssey 19.395–412, and for the night mission that requires stealth. Petegorsky (1982:200) also argues that the helmet connects all of these elements of Odysseus’ identity: “This helmet functions as a kind of identity marker for Odysseus, and it is in effect the equivalent of the scar in Odyssey Nineteen, which was the result of a wound inflicted on the hero by the tusk of a boar.”