Also:All the confusion and disagreement surrounding both the author and the wording of this saying led us to suspect that it may be a simple maxim, not attributable to any single person -- which is not to question its wisdom.
Proverbs 17:28 Even a fool, when he holdeth his peace, is counted wise: and he that shutteth his lips is esteemed a man of understanding.
Proverbs 29:11 A fool uttereth all his mind: but a wise man keepeth it in till afterwards.
Proverbs 29:20 Seest thou a man that is hasty in his words? there is more hope of a fool than of him.
Agreed, I was taught the Thomas Aquinas said it first but I really dont know either