The gift of a quick and ready intellect is to lead to high office, it is not to be wasted on a work to which the obscure are adequate.

He shalt not stand before mean men - חשכים chashukkim, dark or obscure persons; men of no repute. Na he schal ben before un-noble men - Old MS. Bible. "Not amonge the symple people." - Coverdale.
The general meaning of the proverb is, "Every diligent, active man, shall be at once independent and respectable."

Seest thou a man diligent in his business?.... In the business of his calling, be it what it will, whether for himself or his master; constant in it, swift, ready, and expeditious at it; who industriously pursues it, cheerfully attends it, makes quick dispatch of it; does it off of hand, at once, and is not slothful in it, nor weary of it; when you have observed and taken notice of such a man, which is not very common, you may, without a spirit of prophecy, foresee that such a man will rise in the world;
he shall stand before kings; he shall not stand before mean men, or "obscure persons" (o); he shall not continue in the service of ignoble persons, or keep company with them; but he shall be taken into the service of princes and noble men, and be admitted into their presence, and receive favours from them; as Joseph, who was industrious and diligent in his business in Potiphar's house, was in process of time advanced, and stood before Pharaoh king of Egypt, Genesis 39:4. This may be spiritually applied. Every good man has a work or business to do in a religious way; some in a higher sphere, as officers of churches, ministers and deacons; the work of the one lies in reading, study, meditation, and prayer, in the ministration of the word and ordinances, and other duties of their once; and the business of the others in taking care of the poor, and the secular affairs of the churches; others in a lower way, and common to all Christians, which lies in the exercise of grace, and performance of all good works, relative to themselves, their families, and the church of God. Now ministers that are diligent in teaching and ruling; and deacons that do their office well; and private Christians, who are steadfast and immovable, always abounding in the work of the Lord; are ready to every good work, heartily engaged in it, and constantly at it; shall not be company for the sons of darkness, unregenerate men, who are in the dark, and darkness itself; what communion has light with darkness, with works of darkness, they should be not workers of? or have any fellowship with the prince of darkness, from whose power they are delivered; but shall have society with the saints, who are made kings and priests unto God; shall be admitted into the presence of the King of kings now, and have communion with him; and shall stand before him at the great day with confidence, and not be ashamed; shall stand at his right hand, and shall be for ever with him. So the Jews (p) interpret this place, "he shall not stand before dark ones", in hell; "he shall stand before kings", in the garden of Eden, in paradise; that is, in heaven.
(o) "ante obscuros", Mercerus, Junius & Tremellius, Piscator; "coram obscuris", Cocceius, Gejerus, Michaelis; "in conspectu obscurorum", Schultens. (p) Gloss. in T. Bab. Sanhedrin, fol. 104. 2.

Success rewards diligence (Proverbs 10:4; Proverbs 21:5).

After these four proverbs beginning with אל, a new series begins with the following tristich:
29 Seest thou a man who is expert in his calling -
Before kings may he stand;
Not stand before obscure men;
i.e., he can enter into the service of kings, and needs not to enter into the service of mean men = he is entitled to claim the highest official post. חזית, in Proverbs 26:12 = Proverbs 29:20, interchanging with ראית, is perf. hypotheticum (cf. Proverbs 24:10; Proverbs 25:16): si videris; the conclusion which might begin with דּע כּי expresses further what he who sees will have occasion to observe. Rightly Luther: Sihestu einen Man endelich (vid., at Proverbs 21:5) in seinem geschefft, u.s.w. = seest thou a man expert in his business, etc.. מהיר denotes in all the three chief dialects one who is skilful in a manner not merely by virtue of external artistic ability, but also by means of intellectual mastery of it. התיצּב לפני, to enter on the situation of a servant before any one; cf. Job 1:6; Job 2:1. עמד לפני, 1-Samuel 16:21; 1-Kings 10:8. Along with the pausal form יתיצּב, there is also found in Codd. the form יתיצּב (the ground-form to יתיצּב, whence that pausal form is lengthened), which Ben-Bileam defends, for he reckons this word among "the pathachized pausal forms." חשׁכּים, in contrast to מלכים, are the obscuri = ignobiles. The Targ. translate the Hebrews. דּל and אביון by חשׁיך and חשׁוך. Kimchi compares Jeremiah 39:10, where העם הדּלּים is translated by חשׁיכיּא (cf. 2-Kings 24:14; 2-Kings 25:12). חלכּה (חלכּה) is the old Hebrews. synonym in Ps 10. The poet seems here to transfer the Aram. usus loq. into the Hebrews.

Before kings - He is fit to be employed in the affairs of princes.