Aql-mand ko ek ishaara hi kaafi hota hai. For a wise person, a single hint is enough. The Rekhta dictionary lists the proverb in Hindi and Urdu.
A harsher proverb makes the same point: ghodi ko ishaara kaafi hai, gadhe ko laathiyaan peeta karo. A hint is enough for a mare. A donkey has to be beaten.