Where does “Afganistan” come from?

Afganistan (Faroese) comes from Persian افغان, from Sogdian ʾβγʾn.

Ancestry of “Afganistan”, step by step

Step	Language	Word	Meaning
1	Persian	افغان	Afghan; Pashtun; API •
2	Sogdian	ʾβγʾn	—

Afganistan — Etymology, Origin & Word History | Etymology Explorer