Tasmat Tvam Indriyanyaadau

Now comes the battle plan. Desire has three strongholds: senses, mind, intellect. Krishna says start at the outermost ring — the senses. Bring them under control first. When the gates are guarded, the invader cannot enter so easily.

Then strike. Destroy this enemy that eats both jnana (theoretical knowledge) and vijnana (experiential wisdom, direct realization). The word 'prajahi' is a command a general gives on the battlefield: slay it. There is no room for half-measures. Krishna addresses Arjuna as Bharatarshabha — the bull among the Bharatas — reminding him of his warrior nature. You have the strength for this fight.

This is the practical solution to the problem described in 3.40. Since desire resides in the senses, begin there. Gita 3.7 also said: 'controlling the senses with the mind.'

Verses 3.42 and 3.43 will describe the hierarchical ladder — senses, mind, intellect, and beyond — that maps the path upward to final victory over desire.