Plural of a Homeric word (singular at kappa 1512), glossed with the Attic be/lh as early as Aristonicus, De signis Iliadis 11.584, 12.280. Apion, Fragmenta de glossis Homericis vol 74 p. 243 Ludwich glosses it as both be/lh and shmei=a. Ludwich identifies the former with Homer, Iliad 1.383 "then the people began to die thick and fast, and the shafts of the god ranged everywhere", and the latter with Iliad 12.280 "when Zeus the counsellor moves himself to snow, exhibiting to men these arrows of his". (Those "arrows", as Aristonicus explains, are snow and rain.) The distinction is repeated in Apollonius' Homeric Lexicon (99.2), Hesychius kappa2488, and the Epimerismi (9 CE?) with the nearly identical phrasing be/lh, o(te\ shmei=a; the phrasing also occurs in the Etymologicum Magnum and the scholia to Iliad 1.53.
The shmei=a gloss in turn led the Etymologicum Gudianum to associate kh=la several times with dh=la, "conspicuous [things]"; e.g. s.v. kh=la "certain conspicuous things which are apparent; from kai/w 'burn'; properly they refer to lightning and hurricanes".