Hebrews 2:14
6 Next he sets down also the cause of the economy. “That through death,” he says, “He might destroy him that had the power of death, that is, the devil.”
Here he points out the wonder, that by what the devil prevailed, by that was he overcome, and the very thing which was his strong weapon against the world, [namely], Death, by this Christ smote him. In this he exhibits the greatness of the conqueror's power. Do you see how great good death has wrought?
Source: Homilies on the Epistle to the Hebrews (New Advent)