Dale Tuggy documented Rufinus mistranslating Origen to add a Nicean, Trinitarian spin that was not in Origen.
On such passage jumped out at me just now, in On First Principles IV.2.7. Here’s the Greek as related by Basil and Gregory:
And when we speak of the needs of souls, who cannot otherwise reach perfection except through the rich and wise truth about God, we attach of necessity pre-eminent importance to the doctrines concerning God and His only begotten Son; of what nature the Son is, and in what manner he can be the Son of God…
Note that Origen uses “God” three times here, each time obviously meaning the Father only.
Here is Rufinus’ Latin rendering, or rather, re-write.
For in no other way can the soul reach the perfection of knowledge except by being inspired with the truth of the divine wisdom. Therefore, it is chiefly the doctrine about God, that is, about the Father, Son, and Holy Spirit, which is indicated by those men who were filled with the divine Spirit. Then too the mysteries relating to the Son of God… (Origen, On First Principles, trans. Butterworth, p. 283, emphases added)