Bhagavad Gita, Chapter 18, Verse 74

Sanjaya said: Thus have I heard this wonderful dialogue between Vâsudeva and the high-souled Pârtha, causing my hair to stand on end.

Even Sanjay, only narrating from outside, is described here as physically moved by what he's witnessed.

Real, involuntary reaction, hair standing on end, marks Sanjay's own response to this dialogue, not just Arjun's. The impact of this conversation is shown reaching beyond its two original participants.