Gold - The "choice, fine gold" of margin reference. The "fine gold" in the second clause is a different word, and perhaps represents gold extracted from the ore.

My fruit is better than gold, yea, than fine gold,.... This is said in allusion to the fruit that grows on trees, Wisdom, or Christ, being a tree of life; see Gill on Proverbs 3:18; and so he is compared to other trees, Song 2:3. His "fruit" are the blessings of grace, such as redemption, reconciliation, pardon, justification, adoption, and eternal life; these are his by covenant, are procured by him, and are communicated from him; also the graces of his Spirit called fruits, as faith, hope, love, &c. of which he is the author and object; and even good works, the fruits of his grace; they are done in virtue of union to him, by his strength, and are directed to his glory: and all these, especially his grace and the blessings of it, are preferable to the finest gold; they are more valuable as to their intrinsic worth and excellency; they are more useful and profitable, being for the good and welfare of immortal souls; and they are more satisfying and more lasting, and which cannot be obtained with such a corruptible thing as gold is;
and my revenue than choice silver; as the former word refers to fruits that grow on trees, this to such as spring from seed sown in the earth; see Leviticus 23:39, where the same word is used as here, and is also rendered "revenue" in Jeremiah 12:13; Christ himself is compared to seed, and so his word, John 12:24; and the fruit or revenue thereof is the same as before: or else the allusion is to the profit arising from riches, from estates, and their annual rent; or from money put out to use, or improved by commerce, and so signifies the same with the gain and merchandise of wisdom; see Gill on Proverbs 3:14. Aben Ezra construes the words thus, "my revenue is choicer than silver"; but our version is best.

(Compare Proverbs 8:11; Proverbs 3:16).