כָּל־עָ֭רוּם יַעֲשֶׂ֣ה בְדָ֑עַת וּ֝כְסִ֗יל יִפְרֹ֥שׂ אִוֶּֽלֶת׃
Todo hombre cuerdo obra con sabiduría: Mas el necio manifestará necedad.
Rashi on Proverbs
Every cunning man acts with forethought He performs his deeds with forethought, like David: “Let them seek for my lord, the king, a young girl, a virgin, etc.” (I Kings 1:2).
Rashi on Proverbs
but a fool exposes [his] stupidity This is Ahasuerus (Esther 2:3): “Let the king appoint, etc.” They knew that he would not marry them all. Therefore, whoever had a daughter concealed her.