Where does “Покистон” come from?

Покистон (Tajik) comes from Persian پاکستان, from Urdu پاکستان, from Classical Persian پَاک.

Ancestry of “Покистон”, step by step

StepLanguageWordMeaning
1Persianپاکستان—
2UrduپاکستانLand of the Pure
3Classical Persianپَاک—
Every word from Classical Persian پَاک →Every word from Urdu پاکستان →Every word from Persian پاکستان →