Where does “ἄε” come from?

ἄε (Greek) comes from Ancient Greek ἄγε, from Ancient Greek ἄγω, from Proto-Hellenic ágō, from Proto-Indo-European h₂éǵeti, from Proto-Indo-European h₂eǵ- — to drive.

Ancestry of “ἄε”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ἄγε	second-person singular present active imperative...
2	Ancient Greek	ἄγω	to lead, fetch, bring along (a living creature), take with
3	Proto-Hellenic	ágō	to lead, to guide
4	Proto-Indo-European	h₂éǵeti	to be driving
5	Proto-Indo-European	h₂eǵ-	to drive

Every word from Proto-Indo-European h₂eǵ- →Every word from Proto-Indo-European h₂éǵeti →Every word from Proto-Hellenic ágō →