Solomon
Proverbs 12:5ESV·traditional attribution

The thoughts of the righteous are just; the counsels of the wicked are deceitful.

Matthew Henry Presbyterian @wholebiblehenry

Note, 1. The word of God is a discerner of the thoughts and intents of the heart, and judges them. We mistake if we imagine that thoughts are free. No, they are under the divine cognizance, and therefore under the divine command. 2.

John Gill Reformed Baptist @doctorgill

The thoughts of the righteous are right,.... Or "judgment" (o). The thoughts of men's hearts are naturally evil, nor can any think a good thought of themselves; but the thoughts of the righteous are directed and influenced by the grace of God, and are formed according to that Word which is a discerner of the thoughts and intents of the heart; their thoughts concerning God...

Jamieson-Fausset-Brown Reformed @jfbcommentary

thoughts--or, "purposes." are right--literally, "are judgment," that is, true decisions. counsels--(Compare Pro 11:14). deceit--contrary to truth and honesty.