Nicene and Post-Nicene Fathers, Ser. II, Vol. III:
Life and Works of Rufinus with Jerome's Apology Against Rufinus.: Chapter 8(2)

8 (2). We will pass on to clear up another of the charges, if only he will confess under the stress of his own consciousness of wrong that he has been convicted both of perjury and of making a false defence. Otherwise, if he attempts to deny what I say, I can produce as witnesses any number of my brethren, who, while living in the cells built by me on the Mount of Olives, copied out for him most of the Dialogues of Cicero. I often, as they wrote them out, p. 465 had in my hands quaternions 2954 of these Dialogues; and I looked them over myself, in recognition of the fact that he gave them much larger pay than is usually given for writings of other sorts. He himself also came to see me at Jerusalem from Bethlehem, bringing with him a book which contained a single Dialogue of Cicero, and also one of Plato’s in Greek; he will not pretend to deny having given me that book, and having stayed some time with me. But what is the use of delaying so long over a matter which is clearer than the light? To all that I have said this addition is to be made, after which all further comment is superfluous; that after he had settled in the monastery at Bethlehem, and indeed not so long ago, he took the office of a teacher in grammar, and explained ‘his own’ Maro and the comedians and lyrical and historical writers to young boys who had been entrusted to him that he might teach them the fear of the Lord: so that he actually became a teacher and professor in the knowledge of those heathen authors, as to whom he had sworn that if he even read them he would have denied Christ.

Footnotes

Quaterniones may mean ‘sets of four.’ It likely to be used for a ‘cahier’ of four sheets.