Charles Ellicott Commentary Proverbs 4:18

"But the path of the righteous is as the dawning light, That shineth more and more unto the perfect day." — Proverbs 4:18 (ASV)

But the path of the just... — The just have the Lord for their light (Psalms 27:1); on them the Sun of righteousness has arisen (Malachi 4:2), as the light of the morning, even a morning without clouds (2 Samuel 23:4). And this light, that is, their knowledge of God, will become clearer and clearer until the perfect day, when they shall see Him as He is (1 John 3:2). (and Notes on Proverbs 6:23.)