Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary
Another proverb continues the commendation of the effective word; for it represents, in emblem, the interchangeable relation of speaker and hearer:
A golden earring and an ornament of fine gold -
A wise preacher to an ear that heareth;
i.e., as the former two ornaments form a beautiful ensemble, so the latter two, the wise preacher of morality and an attentive ear, form a harmonious whole: על, down upon, is explained by Deu 32:2. נזם, at Pro 11:12, standing along with באף, meant a ring for the nose; but here, as elsewhere, it means an earring (lxx, Jerome, Venet.), translated by the Syr. and Targ. by קדשׁא, because it serves as a talisman. A ring for the nose
(Note: Vid., Gieger's Zeitschrift, 1872, pp. 45-48, where it is endeavoured to be shown that נזם, as an earring, is rejected from the later biblical literature, because it had become "an object used in the worship of idols," and that the word was used only of a ring for the nose as a permissible ornament, while עגיל was used for the earring. But that does not apply to the Solomonic era; for that, in the passage under review, נזם signifies a ring for the nose, is only a supposition of Geiger's, because it accords with his construction of history.)
cannot also be here thought of, because this ornament is an emblem of the attentive ear: willingly accepted chastisement or instruction is an ear-ornament to him who hears (Stier). But the gift of the wise preacher, which consists in rightly dividing the word of truth, Ti2 2:15, is as an ornament for the neck or the breast חלי (= Arab. khaly, fem. חליה = ḥilyt), of fine gold (כּתם, jewel, then particularly precious gold, from כּתם, Arab. katam, recondere).
(Note: Hitzig compares Arab. kumêt; but this means bayard, as Lagarde remarks, the Greek κόμαιθος; and if by כתם gold foxes (gold money) are to be thought of, yet they have nothing whatever to do with bayards (red-brown horses); cf. Beohmer, de colorum nominibus equinorum, in his Roman. Stud. Heft 2, 1872, p. 285.)
The Venet. well: κόσμος ἀπυροχρύσου (fine gold); on the contrary (perhaps in want of another name for gold), כתם is translated, by the lxx and Syr., by sardine; by the Targ., by emerald; and by Jerome, by margaritum.
(Note: Another Greek translates πίνωσις χρυσῆ. This πίνωσις is a philological mystery, the solution of which has been attempted by Bochart, Letronne, and Field.)
It looks well when two stand together, the one of whom has golden earrings, and the other wears a yet more precious golden necklace - such a beautiful mutual relationship is formed by a wise speaker and a hearer who listens to his admonitions.
John Gill Bible Commentary
As an earring of gold, and an ornament of fine gold,.... As a golden earring, when first put on, gives pain and uneasiness; but, being well hung and fixed, is very ornamental, being of fine gold, and especially when any jewels are upon it; which may be meant by the ornament, as the word is rendered, Sol 7:1;
so is a wise reprover upon an obedient ear; such is the reproof of a wise man, which is seasonably given, in a fit and proper manner; and which appears to proceed from love, and is designed for good, and done in great affection and faithfulness: this, though it may be a little grating to the ear at first, yet, when well considered and received, instead of leaving any infamy or reproach on the person reproved, it is an ornament to him, as well as reflects honour upon the reprover. It may be rendered, "so is he that reproveth a wise man, upon" or "with an obedient ear" (g); a wise man that has an obedient or hearing ear, who is so wise as to altered to reproofs given him, and which he takes kindly, and receives profit and advantage from them; see Pro 9:8.
(g) "qui arguit sapientem", V. L. Pagninus, Mercerus, Gejerus.