Solomon
Proverbs 8:9ESV·traditional attribution

They are all straight to him who understands, and right to those who find knowledge.

Matthew Henry Presbyterian @wholebiblehenry

The will of God revealed to us for our salvation is here largely represented to us as easy to be known and understood, that none may have an excuse for their ignorance or error, and as worthy to be embraced, that none may have an excuse for their carelessness and unbelief. I.

Commenting on Proverbs 8:1-11

John Gill Reformed Baptist @doctorgill

They are all plain to him that understandeth,.... Whose understanding is enlightened by the Spirit of God; who is a spiritual man, that has a discerning, and can judge of spiritual things: as for the carnal man, let him have what natural knowledge or wisdom he will, he cannot know these things; for they are spiritually discerned, and can only be discerned by spiritual men.

Jamieson-Fausset-Brown Reformed @jfbcommentary

plain . . . understandeth--easily seen by those who apply their minds. that find--implying search.