the specific word for coin.^[1]

Mendelssohn-Friedländer also explains: “He who loveth silver is not satisfied with silver,” i.e., it does not make him full; that might perhaps be linguistically possible (cf. e.g., Pro 12:11), although the author would in that case probably have written the words מן־הכּסף, after Ecc 6:3; but “to be not full of money” is, after Ecc 1:8, and especially Ecc 4:8, Hab 2:5, cf. Pro 27:20 = never to have enough of money, but always to desire more.
That which follows, Ecc 5:9, is, according to Hitz., a question: And who hath joy in abundance, which bringeth nothing in? But such questions, with the answer to be supplied, are not in Koheleth's style; and what would then be understood by capital without interest? Others, as Zöckler, supply ישׂבּע: and he that loveth abundance of possessions (is) not (full) of income; but that which is gained by these hard ellipses is only a tautology. With right, the Targ., Syr., Jerome, the Venet., and Luther take lo tevuah as the answer or conclusion; and who clings to abundance of possessions with his love? - he has no fruit thereof; or, with a weakening of the interrog. pronoun into the relative (as at Ecc 1:9; cf. under Psa 34:13): he who ... clings has nothing of it. Hamon signifies a tumult, a noisy multitude, particularly of earthly goods, as at Psa 37:16; 1Ch 29:16; Isa 60:5. The connection of אהב with ב, occurring only here, follows the analogy of חפץ בּ and the like. The conclusion is synon. with levilti ho'il; e.g., Isa 44:10; Jer 7:8. All the Codd. read לא; לו in this sense would be meaningless.^[2]
The designation of advantage by tevuah, the farmer enjoys the fruit of his labour; but he who hangs his heart on the continual tumult, noise, pomp of more numerous and greater possessions is possible, to him all real profit -  i.e., all pleasant, peaceful enjoyment - is lost. With the increase of the possessions there is an increase also of unrest, and the possessor has in reality nothing but the sight of them.

Verse 11

Ecc 5:11 “When property and goods increase, they become many who consume them; and what advantage hath the owner thereof but the sight of them with his eyes?” The verb רבה signifies to increase, the רבב, to be many; but also (which Böttch. denies) inchoatively: to become many, Gen 6:1; rightly, the lxx, ἐπληθύνθησαν.

1. ↑ A Jewish fancy supposes that כסף is chosen because it consists of letters rising in value (20, 60, 80); while, on the contrary, זהב consists of letters decreasing in value (7, 5, 2).
2. ↑ In Maccoth 10a, לו is read three times in succession; the Midrash Wajikra, c. 22, reads לא, and thus it is always found without Kerı̂ and without variation.