Albert Barnes Commentary Proverbs 3:18

"She is a tree of life to them that lay hold upon her: And happy is every one that retaineth her." — Proverbs 3:18 (ASV)

This and the other references in Proverbs (Proverbs 11:30; Proverbs 13:12; Proverbs 15:4) are the only allusions in any book of the Old Testament, after Genesis, to the “tree” itself, or to its spiritual significance. Further, there is the tendency to a half-allegorizing application of that history.

The tree of life which Adam was not to taste lies open to his children. Wisdom is the tree of life, giving a true immortality.

The symbol entered largely into the religious imagery of Assyria, Egypt, and Persia. Philo, going a step further, found in the two trees the ideal representatives of speculative knowledge and moral wisdom; and the same image serves a higher purpose in the promises and the visions of (Revelation 2:7); (Revelation 22:2).