Wisdom strengtheneth the wise - One wise, thoroughly learned, and scientific man, may be of more use in fortifying and defending a city, than ten princes. Witness the case of Syracuse, when attacked by the Romans both by sea and land. Archimedes, by his engines, burnt and dashed their fleet to pieces, and destroyed all that came near the walls. And had not the city been betrayed and he killed, all their force and skill could not have taken it.

Wisdom strengtheneth the wise,.... Against such extremes as before mentioned; it is a guard about him, as well as a guide unto him; it is a defence unto him, as before observed, Ecclesiastes 7:12; and is better than strength of body, or weapons of war, Ecclesiastes 9:16; and a wise man does greater things by it than a strong man with them, and is safer with it than he can be by them. Some understand this of Christ, the Wisdom of God, without whom a good man can do nothing, but all things through him strengthening him; and who being a strong tower and place of refuge to him, he is safer in him than if he was in the strongest garrison, and under the protection of ever so large a number of valiant men: Christ, and grace from him, strengthen
more than ten mighty men which are in the city; that is, than many mighty men, or men of war, which guard a city; the city of Jerusalem, or any other. The Targum applies this to Joseph, and paraphrases it,
"the wisdom of Joseph the son of Jacob helped him to make him wiser than all his ten righteous brethren.''

Hebrew, "The wisdom," that is, the true wisdom, religion (2-Timothy 3:15).
than ten mighty--that is, able and valiant generals (Ecclesiastes 7:12; Ecclesiastes 9:13-18; Proverbs 21:22; Proverbs 24:5). These "watchmen wake in vain, except the Lord keep the city" (Psalm 127:1).

"Wisdom affords strong protection to the wise man more than ten mighty men who are in the city." We have to distinguish, as is shown under Psalm 31:3, the verbs עזז, to be strong, and עוּז, to flee for refuge; תּעז is the fut. of the former, whence מעז, stronghold, safe retreat, protection, and with ל, since עזז means not only to be strong, but also to show oneself strong, as at Eccl 9:20, to feel and act as one strong; it has also the trans. meaning, to strengthen, as shown in Psalm 68:29, but here the intrans. suffices: wisdom proves itself strong for the wise man. The ten shallithim are not, with Ginsburg, to be multiplied indefinitely into "many mighty men." And it is not necessary, with Desvoeux, Hitz., Zckl., and others, to think of ten chiefs (commanders of forces), including the portions of the city garrison which they commanded. The author probably in this refers to some definite political arrangement, perhaps to the ten archons, like those Assyrian salaṭ, vice-regents, after whom as eponyms the year was named by the Greeks. שׁלּיט, in the Asiatic kingdom, was not properly a military title. And did a town then need protection only in the time of war, and not also at other times, against injury threatening its trade, against encroachments on its order, against the spread of infectious diseases, against the force of the elements? As the Deutero-Isaiah (Isaiah 60:17) says of Jerusalem: "I will make thy officers peace, and thine exactors righteousness," so Koheleth says here that wisdom affords a wise man as strong a protection as a powerful decemvirate a city; cf. Proverbs 24:5: "A wise man is ba'oz," i.e., mighty.

Strengthen - Supports him in, and secures him against troubles and dangers.