[1] From the scholia to Homer, Iliad 5.343, where the headword verb occurs (in the indicative). The purpose of the entry - difficult to convey in translation - is to illustrate the phenomenon, found in several Greek dialects, where kataballein and other such verbs become kabballein. Cf. kappa 2.
[2] Ameipsias fr.13 Kock; already at alpha 2142.