Proverbs 11:30

This shows what great blessings good men are, especially those that are eminently wise, to the places where they live, and therefore how much to be valued. 1. The righteous are as trees of life; the fruits of their piety and charity, their instructions, reproofs, examples, and prayers, their interest in heaven, and their influence upon earth, are like the fruits of that tree, precious and useful, contributing to the support and nourishment of the spiritual life in many; they are the ornaments of paradise, God's church on earth, for whose sake it stands. 2. The wise are something more; they are as trees of knowledge, not forbidden, but commanded knowledge. He that is wise, by communicating his wisdom, wins souls, wins upon them to bring them in love with God and holiness, and so wins them over into the interests of God's kingdom among men. The wise are said to turn many to righteousness, and that is the same with winning souls here, Dan 12:3. Abraham's proselytes are called the souls that he had gotten, Gen 12:5. Those that would win souls have need of wisdom to know how to deal with them; and those that do win souls show that they are wise.

— Matthew Henry's Concise Commentary (public domain)

a tree of life--Blessings to others proceed from the works of the righteous (Pro 3:18). winneth souls--(Compare Margin) to do them good as opposed to Pro 6:25; Eze 13:18 (compare Luk 5:10).

— Jamieson-Fausset-Brown Commentary (public domain)