Tradition
St. Hilary of Poitiers
On the Trinity
Book 10 › Section 13
13. But was it perhaps the physical pain of hanging on the cross, or the rough cords with which He was bound, or the cruel wounds, where the nails were driven in, that dismayed Him? Let us see of what body the Man Jesus was, that pain should dwell in His crucified, bound, and pierced body.
Source: On the Trinity (New Advent)