अहो बत महत्पापं कर्तुं व्यवसिता वयम्।यद्राज्यसुखलोभेन हन्तुं स्वजनमुद्यताः॥
aho bata mahat pāpaṃ kartuṃ vyavasitā vayamyad rājya-sukha-lobhena hantuṃ sva-janam udyatāḥ
Word by word
The verse says
Alas — we have set our minds on a great crime, ready to kill our own people out of greed for the pleasures of a kingdom.
In plain words
The doctrine drops away and his own voice comes back.
Alas. And then he includes himself: we have resolved on a great sin, out of greed.
It is the first time he has put himself on the same side as the men he called blinded by greed in verse 38. He is no longer standing above the war.
Where you've felt this · in failure
Partway through blaming someone else, the sentence turns and you find yourself inside it. You were going to say what they did. What comes out is what we did, and the argument you were winning quietly ends.
Going deeper
Aho bata — alas, alas. It is a cry, not an argument, and the recitation ends with it.
The honesty here is real. In verse 38 he described the enemy as lobhopahata-cetasaḥ, minds overcome by greed. Now he uses rājya-sukha-lobhena — greed for the pleasures of a kingdom — of himself and his brothers. The same failing, no longer sorted by side.
This is as close as Arjuna gets to seeing clearly in Chapter 1, and it is still not enough to move him. Seeing that both sides are caught in the same thing does not tell him what to do. It only makes him sadder.
That gap is precisely what the Gita exists to fill. Arjuna has reached the limit of what self-examination can do for him on its own. He can see his situation accurately and he still cannot stand up. Everything Krishna says from here is addressed to a man who has already been honest with himself and found that honesty was not sufficient.