"Delight," high unrestrained enjoyment, is to the "fool" who lacks wisdom but a temptation and a snare. The second clause carries the thought on to what the despotism of Eastern monarchies often presented, the objectionable rule of some favored slave, it might be, of alien birth, over the princes and nobles of the land.

Delight is not seemly for a fool - תענוג taanug, splendid or luxurious living, rank, equipage, etc. These sit ill on a fool, though he be by birth a lord.
For a servant to have rule over princes - I pity the king who delivers himself into the hands of his own ministers. Such a one loses his character, and cannnot be respected by his subjects, or rather their subjects. But it is still worse when a person of mean extraction is raised to the throne, or to any place of power; he is generally cruel and tyrannical.

(c) Delight is not proper for a fool; much less for a servant to have rule over princes.
(c) The free use of things are not to be permitted to him who cannot use them correctly.

Delight is not seemly for a fool,.... Such an one as Nabal, whose name and nature were alike; and whose prosperity ill became him, and the mirth and delight he had in it, 1-Samuel 25:25; for, as the wise man elsewhere says, "the prosperity of fools shall destroy them", Proverbs 1:26; they do not know how to make a right use of their prosperity; nor to moderate their enjoyments, pleasures, and delights. Some understand this of spiritual delight in the Lord; in his ways and ordinances, which wicked men are strangers to: and a very uncomely thing it is for such persons to talk of spiritual joy and delight, and of their communion with God, when they live in sin;
much less for a servant to have rule over princes; this was a sight which Solomon had seen, but was very disagreeable to him; and was one of the four things the earth cannot bear; the insolence of a servant, when he becomes master over his superiors, is intolerable; see Proverbs 30:22. It may be spiritually applied to such who are servants of sin; to whose sensual appetites and carnal affections the more noble and princely powers of the soul, the understanding and mind, become subject; which is very improper and unseemly.

A man that has not wisdom and grace, has no right or title to true joy. It is very unseemly for one who is a servant to sin, to oppress God's free-men.

(Compare Proverbs 17:7). The fool is incapable of properly using pleasure as knowledge, yet for him to have it is less incongruous than the undue elevation of servants. Let each abide in his calling (1-Corinthians 7:20).

10 Luxury becometh not a fool;
How much less a servant to rule over princes.
Thus also with לא נאוה (3 p. Pil. non decet, cf. the adj. Proverbs 26:1) Proverbs 17:7 begins. אף כּי rises here, as at Proverbs 19:7, a minori ad majus: how much more is it unbecoming = how much less is it seemly. The contrast in the last case is, however, more rugged, and the expression harsher. "A fool cannot bear luxury: he becomes by it yet more foolish; one who was previously a humble slave, but who has attained by good fortune a place of prominence and power, from being something good, becomes at once something bad: an insolent sceleratus" (Fl.). Agur, xxx. 22f., describes such a homo novus as an unbearable calamity; and the author of the Book of Ecclesiastes, written in the time of the Persian domination, speaks, Ecclesiastes 10:7, of such. The lxx translates, καὶ ἐὰν οἰκέτης ἄρξηται μεθ ̓ ὕβρεως δυναστεύειν, rendering the phrase כּשׂרים by μεθ ̓ ὕβρεως, but all other translators had בּשׂרים before them.

Delight - To live in pleasure and outward glory, doth not become him, nor suit with him; because prosperity corrupts even wise men, and makes fools mad; and because it gives him more opportunity to discover his folly, and to do mischief both to himself and others.