A buen entendedor, pocas palabras bastan / A word is enough to the wise

You can use it in a good sense (to praise somebody’s intelligence) or in a negative one (to let show someone that another person does not want to understand what is talked about and not because he/she does not understand).

Intelligent people can take hints; they don’t need to have everything explained to them at great length.

It comes from Plautus’s sentence: “Intelligenti pauca”, which is to point out that who has a good understanding does not require lengthy explanations to understand something.