Wisdom is a defense - See the margin and Psalm 121:5, i. e., He who is defended from adversity by his wisdom is in as good a position as he who is defended by his riches.
Excellency - literally, Profit.
Giveth life to - literally, "Causes to live," "makes alive" Proverbs 3:18; the deeper meaning of which is elicited by comparing these words with John 6:63; Matthew 4:4.

Wisdom is a defense - To whom Solomon answers: All true wisdom is most undoubtedly a great advantage to men in all circumstances; and money is also of great use: but it cannot be compared to wisdom. Knowledge of Divine and human things is a great blessing. Money is the means of supporting our animal life: but wisdom - the religion of the true God - gives life to them that have it. Money cannot procure the favor of God, nor give life to the soul.

For wisdom is a defence, and money is a defence,.... Or, a "shadow" of refreshment and protection, under which men sit with pleasure and safety; a man by his wisdom, and so by his money, is able to defend himself against the injuries and oppressions of others, and especially when both meet in one and the same man. Jarchi renders and interprets it,
"he that is in the shadow of wisdom is in the shadow of money, for wisdom is the cause why riches come;''
and so the Targum,
"as a man is hid in the shadow of wisdom, so he is hid in the shadow of money, when he does alms with it;''
compare with this Luke 16:9; see Ecclesiastes 7:19. Theognis (o) has a saying much like this,
"riches and wisdom are always inexpugnable to mortals;''
but the excellency of knowledge is, that wisdom giveth life to them that have it; or, "the excellency of the knowledge of wisdom giveth life" (p), &c. not of natural wisdom, or the knowledge of natural and civil things, the vanity of this is exposed, before by the wise man; but the knowledge of God in Christ; the knowledge of Christ, who is the Wisdom of God; and of the Gospel, and of all divine and spiritual things: this is a superior excellency to riches, which often expose a man's life to danger, cannot preserve him from a corporeal death, much less from an eternal one. When this is the excellency of spiritual knowledge, that spiritual life goes along with it; such as are spiritually enlightened are spiritually quickened; live by faith on Christ, whom they know; and, through the knowledge of him, have all things pertaining to life and godliness, and have both a right and meetness for eternal life; yea, this knowledge is life eternal, John 17:3; see 2-Peter 1:3; and this is the pure gift of Wisdom, or of Christ, and not owing to the merit of men, or works done in obedience to the law, which cannot give this life; see John 17:2, Romans 6:23.
(o) Sententiae, v. 1153. (p) "et praestantia scientiae sapientiae vivificabit", Montanus.

Literally, (To be) in (that is, under) the shadow (Isaiah 30:2) of wisdom (is the same as to be) in (under) the shadow of money; wisdom no less shields one from the ills of life than money does.
is, that--rather, "the excellency of the knowledge of wisdom giveth life," that is, life in the highest sense, here and hereafter (Proverbs 3:18; John 17:3; 2-Peter 1:3). Wisdom (religion) cannot be lost as money can. It shields one in adversity, as well as prosperity; money, only in prosperity. The question in Ecclesiastes 7:10 implies a want of it.

Life - But herein knowledge of wisdom excels riches, that whereas riches frequently expose men to destruction, true wisdom doth often preserve a man from temporal, and always from eternal ruin.