Solomon
Proverbs 21:8ESV·traditional attribution

The way of the guilty is crooked, but the conduct of the pure is upright.

Matthew Henry Presbyterian @wholebiblehenry

This shows that as men are so is their way. 1. Evil men have evil ways. If the man be froward, his way also is strange; and this is the way of most men, such is the general corruption of mankind. They have all gone aside (Psa 14:2, Psa 14:3); all flesh have perverted their way.

John Gill Reformed Baptist @doctorgill

The way of man is froward and strange,.... Not the way of any and every man; not the way of righteous and good men, of believers in Christ; who know him, the way, and walk in him and after him, and being led by him; who have his spirit to be their guide, and do walk in his ways, and find pleasure in them; the...

Jamieson-Fausset-Brown Reformed @jfbcommentary

of man--any one; his way is opposed to truth, and also estranged from it. The pure proves himself such by his right conduct.