Bhagavad Gita, Chapter 3, Verse 1

Arjuna said: If, O Janârdana, according to you, knowledge is superior to action, why then, O Keshava, do you engage me in this terrible action?

If knowing is really better than doing, why are you telling me to go fight?

Arjuna isn't being difficult here, he genuinely heard something that sounded contradictory. If wisdom outranks action, the war Krishna's pushing him toward seems like the wrong move entirely.