This wisdom have I seen also under the sun; better, as the Septuagint, This also I saw to be wisdom under the sun. The experience which follows he recognized as an instance of worldly wisdom. To what special event he alludes is quite unknown.
Probably the circumstance was familiar to his contemporaries. It is not to be considered as an allegory, though of course it is capable of spiritual application. The event in Bible history most like it is the preservation of Abel-Beth-maachah by the counsel of the wise woman (whose name is forgotten) narrated in 2 Samuel 20:15-22.
And it seemed great unto me; Septuagint, καὶ μεγάλη ἐστι πρὸς μέ, "And it is great before me." To my mind it appeared an important example (comp. Esther 10:3). Some critics who contend for the Solomonic authorship of our book, see here an allegorical reference to the foreseen revolt of Jeroboam, whose insurrection had been opposed by certain wise statesmen, but had been carried out in opposition to their counsel.
Wordsworth considers that the apologue may be illustrated by the history of Jerusalem, when great powers were arrayed against it in the time of Isaiah, and the prophet by his prayers and exhortations delivered it (2 Kings 19:2, 2 Kings 19:6, 2 Kings 19:20), but was wholly disregarded afterwards, nay, was put to death by the son of the king whom he saved.
But all this is nihil ad rem. As Plautus says, "Haec quidem deliramenta loquitur."