Solomon
Proverbs 21:14ESV·traditional attribution

A gift in secret averts anger, and a concealed bribe, strong wrath.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. The power that is commonly found to be in gifts. Nothing is more violent than anger. O the force of strong wrath! And yet a handsome present, prudently managed, will turn away some men's wrath when it seemed implacable, and disarm the keenest and most passionate resentments. Covetousness is commonly a master-sin and has the command of other lusts. Pecuniae obediunt omnia - Money commands all things.

John Gill Reformed Baptist @doctorgill

A gift in secret pacifieth anger,.... Appeases an angry man; humbles and "brings his anger down" (y), as Aben Ezra and Gersom observe the word signifies; which before rose very high, and showed itself in big words and disdainful looks, as proud wrath does; or extinguishes it, as the Targum and Vulgate Latin version render it, and very fitly.

Jamieson-Fausset-Brown Reformed @jfbcommentary

The effect of bribery (Pro 17:23) is enhanced by secrecy, as the bribed person does not wish his motives made known.