The story
- Proto-Indo-European*ǵʰes-
- Proto-Indo-Iranian*ȷ́ʰástas
- Old Persian𐎭𐎿𐎫 (d-s-t)
- Middle Persian𐭩𐭣𐭤 (ydh)
- Classical Persianدَسْت (dast)?
- Classical Persianدَسْتُور (dastūr)
- English todaydastur
Borrowed from Classical Persian دَسْتُور (dastūr).
Etymology from Wiktionary, CC BY-SA 4.0.