Where does “ख़्वाब” come from?
ख़्वाब (Hindi) comes from Classical Persian خْوَاب, from Middle Persian 𐭧𐭥𐭠𐭡, from Proto-Iranian *hwápati, from Proto-Indo-Iranian swápati, from Proto-Indo-European swép-e-ti, from Proto-Indo-European swep- — to sleep.
ख़्वाब (Hindi): dream
Ancestry of “ख़्वाब”, step by step