It may be in this Chapter: The Death of Christ
"Here, then, is the second reason why the Word dwelt among us, namely that having proved His Godhead by His works, He might offer the sacrifice on behalf of all, surrendering His own temple to death in place of all, to settle man's account with death and free him from the primal transgression. In the same act also He showed Himself mightier than death, displaying His own body incorruptible as the first-fruits of the resurrection…"
The Death of Christ: http://www.ccel.org/ccel/athanasius/incarnation.v.html
That's exactly the chapter, D. Thanks! Blogger, click on that link. Its not a long chapter at all and worth the read. +Athanasius as you know was the first to establish, at least for his Patriarchate, the canon of the NT as we generally know it today.