Solomon
Proverbs 18:20ESV·traditional attribution

From the fruit of a man’s mouth his stomach is satisfied; he is satisfied by the yield of his lips.

Matthew Henry Presbyterian @wholebiblehenry

Note, 1. Our comfort depends very much upon the testimony of our own consciences, for us or against us. The belly is here put for the conscience, as Pro 20:27. Now it is of great consequence to us whether that be satisfied, and what that is filled with, for, accordingly, will our satisfaction be and our inward peace. 2.

John Gill Reformed Baptist @doctorgill

A man's belly shall be satisfied with the fruit of his mouth,.... With his own words and discourses, when they are prudent, pious, and savoury; when they are with grace, and minister it; they are satisfying to himself, to his own mind and conscience, and to his family; to all within his house, which is, as it were, his belly; but, if otherwise, it will...

Jamieson-Fausset-Brown Reformed @jfbcommentary

(Compare Pro 12:14; Pro 13:2). Men's words are the fruit, or, increase of his lips, and when good, benefit them. satisfied with--(Compare Pro 1:31; Pro 14:14).