2 For before the Romans possessed their kingdom, while as yet the Macedonians held Asia, Ptolemy the son of Lagus, being anxious to adorn the library which he had founded in Alexandria, with a collection of the writings of all men, which were [works] of merit, made request to the people of Jerusalem, that they should have their Scriptures translated into the Greek language. And they— for at that time they were still subject to the Macedonians— sent to Ptolemy seventy of their elders, who were thoroughly skilled in the Scriptures and in both the languages, to carry out what he had desired. But he, wishing to test them individually, and fearing lest they might perchance, by taking counsel together, conceal the truth in the Scriptures, by their interpretation, separated them from each other, and commanded them all to write the same translation.
He did this with respect to all the books. But when they came together in the same place before Ptolemy, and each of them compared his own interpretation with that of every other, God was indeed glorified, and the Scriptures were acknowledged as truly divine. For all of them read out the common translation [which they had prepared] in the very same words and the very same names, from beginning to end, so that even the Gentiles present perceived that the Scriptures had been interpreted by the inspiration of God. And there was nothing astonishing in God having done this—He who, when, during the captivity of the people under Nebuchadnezzar, the Scriptures had been corrupted, and when, after seventy years, the Jews had returned to their own land, then, in the times of Artaxerxes king of the Persians, inspired Esdras the priest, of the tribe of Levi, to recast all the words of the former prophets, and to re-establish with the people the Mosaic legislation.
Source: Adversus haereses (New Advent)