Where does “Saleh” come from?

Saleh comes from Arabic صَالِح, meaning "righteous" or "virtuous," borrowed into Persian as صالح.

Ancestry of “Saleh”, step by step

Step	Language	Word	Meaning
1	Persian	صالح	upright, pious
2	Arabic	صَالِح	correct; honest, upright; sound, whole; pious;...
3	Arabic	صالح	in good condition, sound, whole; honest, upright,...
4	Arabic	صَلَحَ	be fit, usable; to be good, right, proper; to be...