Proverbs 3:5 – 6
To trust in the Lord wholeheartedly means one should not rely (lean) on his understanding, for human insights are never enough. God’s ways are incomprehensible (Isa. 55:8–9; Rom. 11:33–34); yet He is trustworthy. All the wisdom a person may acquire can never replace the need for full trust in God’s superior ways. Heart in Hebrew refers to one’s emotions (Prov. 12:25; 13:12; 14:10, 13) but more often to his intellect (such as understanding, 10:8; discernment, 15:14; reflection, 15:28), or will (5:12).
As a person trusts in the Lord and acknowledges Him (this is not a nod of recognition but an intimate knowledge of God) in all his ways (cf. all your heart, 3:5), he finds that God makes his paths straight. This means more than guidance; it means God removes the obstacles, making a smooth path or way of life, or perhaps better, bringing one to the appointed goal. (On ways and paths, cf. v. 17 and see comments on 2:13, 15.) Proverbs teaches that those who follow wisdom have an easier, less problematic life (e.g., 3:10, 16, 24–25).
Buzzell, S. S. (1985). Proverbs. In J. F. Walvoord & R. B. Zuck (Eds.), The Bible Knowledge Commentary: An Exposition of the Scriptures (Vol. 1, p. 911). Wheaton, IL: Victor Books.