Where does “ášpa” come from?

ášpa (Proto-Dardic) comes from Sanskrit अश्व, from Proto-Indo-Aryan Háśwas, from Proto-Indo-Iranian Háćwas, from Proto-Indo-European h₁éḱwos, from Proto-Indo-European h₁oh₁ḱu- — swift.

Ancestry of “ášpa”, step by step

Step	Language	Word	Meaning
1	Sanskrit	अश्व	horse, stallion; knight; the number "seven"
2	Proto-Indo-Aryan	Háśwas	—
3	Proto-Indo-Iranian	Háćwas	horse
4	Proto-Indo-European	h₁éḱwos	stallion, horse
5	Proto-Indo-European	h₁oh₁ḱu-	swift

Every word from Proto-Indo-European h₁oh₁ḱu- →Every word from Proto-Indo-European h₁éḱwos →Every word from Proto-Indo-Iranian Háćwas →