Here is a discussion of how Hebrew makes the superlative: Gesenius' Hebrew Grammar/133. The Comparison of Adjectives. (Periphrastic Expression of the Comparative and Superlative)
http://en.wikisource.org/wiki/Gesenius% ... rlative%29
2. Other periphrases for the superlative are the use of a substantive in the construct state before the plural of the same word (which is naturally to be regarded as a partitive genitive; cf. our book of books), e.g. Ex 2633 קֹדֶשׁ הֲקָּדָשִׁים the most holy place; שִׁיר הַשִּׁירִים (Ct 11) the most excellent song; cf. Gn 925 (= servus servorum, the lowest servant); Nu 332, Dt 1017 (ψ 1362, 3)[8]; 1 K 827, Is 3410 (cf. Gal 1:5, Rev 22:5); Jer 319, Ez 167, 267 (king of kings, of Nebuchadrezzar; cf. 1 Tim 6:15, Rev 17:14, 19:16, and another kind of periphrasis in ψ 953); Ec 12. Similarly in Jer 628 two participles are combined, and in Ho 1015 two substantives in the singular. Finally, the same object is attained by connecting one substantive in the construct state with another of the same stem (שַׁבַּת שַׁבָּתוֹן a sabbath of solemn rest, i.e. an obligatory day of rest, Ex 3115, &c.) or of the same meaning (e.g. ח֫שֶׁךְ אֲפֵלָה a thick darkness, Ex 1022).
But the text in Ecclesiastes does not have the article, like the Hebrew construct would (ματαιότης [τῶν] ματαιοτητων), where I would have expected it. I thought abstract nouns in Greek usually took the article. Here are some of the Greek passages cited above. Some of those passages don't render the Greek with the same syntax as the Hebrew.
Ex 26.33 ἀνὰ μέσον τοῦ ἁγίου καὶ ἀνὰ μέσον τοῦ ἁγίου τῶν ἁγίων.
Num 32.2 καὶ ὁ ἄρχων ἐπὶ τῶν ἀρχόντων τῶν Λευιτῶν Ελεαζαρ
Ct 1.1 Ἆισμα ᾀσμάτων,
Dt. 10.17 οὗτος θεὸς τῶν θεῶν καὶ κύριος τῶν κυρίων,
3 Kingdoms 8.27 εἰ ὁ οὐρανὸς καὶ ὁ οὐρανὸς τοῦ οὐρανοῦ οὐκ ἀρκέσουσίν σοι
1 Tim 6.15 ὁ βασιλεὺς τῶν βασιλευόντων καὶ κύριος τῶν κυριευόντων,
There are phrases in English in which it is hard to understand the meaning: e.g. When Peace like a river attendeth my way. - I guess that's where context comes into play.
Gregorius Nyssenus Theol., In Ecclesiasten (homiliae 8)
Volume 5, page 282, 5.282.10
Εἰ οὖν ἤδη νενόηται ἡμῖν τοῦ ματαίου ἡ ἔννοια, ἐξεταστέον
[5.282.11] ἂν εἴη, τί βούλεται ἡ ματαιότης τῶν ματαιοτήτων. τάχα δ' ἂν
ἡμῖν γνωριμώτερον τὸ ζητούμενον νόημα γένοιτο, εἰ τὴν γρα-
φικὴν συνήθειαν ἐπὶ τῶν πρὸς τὸ κρεῖττον νοουμένων συνεξε-
τάσαιμεν. ἡ τῶν ἀναγκαίων τε καὶ συμφερόντων πρᾶξις ἔργον
[5.282.15] παρὰ τῆς γραφῆς ὀνομάζεται, ἀλλὰ τὰ ὑπερβαίνοντα τῶν
σπουδαζομένων, ὅσα εἰς αὐτὴν ὁρᾷ τὴν τοῦ θεοῦ λατρείαν,
ἔργον ἔργων λέγεται, καθὼς ἡ ἱστορία δηλοῖ, δεικνύντος, οἶμαι,
τοῦ λόγου διά τινος ἀναλογίας ἡμῖν ἐκ τοῦ ἔργου τῶν ἔργων,
τί τὸ ἐν τοῖς σπουδαζομένοις ἐστὶ προτιμότερον. ὃν γὰρ
[5.282.20] ἐπέχει λόγον πρὸς τὴν καθόλου ἀργίαν ἡ περὶ τὰ ἔργα
σπουδή, τὸν αὐτὸν ἔχει λόγον πρὸς τὰ λοιπὰ ἔργα ἡ πρὸς τὰ
ὑψηλότερα καὶ προτιμότερα τῶν σπουδαζομένων ἐνέργεια.
οὕτως καὶ ἅγιόν τι παρὰ τῆς γραφῆς λέγεται· καὶ πάλιν
[5.283.1] ἁγίων ἅγιον, ὡς ἴσῳ τῷ μέτρῳ τοῦ τε ἐξαγίστου τὸ ἅγιον
ὑπερέχειν ἐν ἁγιότητι καὶ τούτου πάλιν τὸ τῶν ἁγίων ἅγιον,
τὸ καθ' ὑπέρθεσιν ἐν ἁγιασμῷ θεωρούμενον. ἅπερ οὖν
ἐπὶ τοῦ κρείττονος ἐδιδάχθημεν λόγου τῆς γραφικῆς συνηθείας
[5.283.5] τῷ τοιούτῳ εἴδει τὴν ἐπίτασιν τοῦ ὑποκειμένου νοήματος
σημαινούσης, τοῦτο καὶ ἐπὶ τῆς τῶν ματαιοτήτων ματαιότη-
τος νοοῦντες οὐ σφαλησόμεθα. λέγει γὰρ οὐχ ἁπλῶς εἶναι
μάταια τὰ ἐν τοῖς οὖσι φαινόμενα, ἀλλὰ καθ' ὑπέρθεσίν τινα
τῆς κατὰ τὸ μάταιον σημασίας εἶναι τοιαῦτα, ὡς εἴ τις λέγοι
[5.283.10] τοῦ νεκροῦ νεκρότερον καὶ τοῦ ἀψύχου ἀψυχότερον. καίτοι
ἡ συγκριτικὴ ἐπίτασις χώραν ἐπὶ τῶν τοιούτων οὐκ ἔχει,
ἀλλ' ὅμως λέγεται τούτῳ τῷ ῥήματι πρὸς τὴν τῆς ὑπερβολῆς
τοῦ δηλουμένου σαφήνειαν. ὥσπερ οὖν ἐστι τὰ ἔργα τῶν
ἔργων καὶ τὰ ἅγια τῶν ἁγίων νοούμενα, δι' ὧν ἡ ὑπερθετικὴ
[5.283.15] πρὸς τὸ κρεῖττον ἔνδειξις ἑρμηνεύεται, οὕτω καὶ ἡ τῶν μα-
ταιοτήτων ματαιότης τὸ ἀνυπέρθετον δείκνυσι τῆς ἐν τῷ
ματαίῳ ὑπερβολῆς