Arjuna closes his three-shloka question with a plea and a declaration of trust. Cut this doubt completely, he says. Asheshatah — leave nothing behind. Do not give me half an answer. Remove the doubt at its root.
Then he adds something deeply personal: there is no one else in the world who can resolve this. Only You. 'Tvad-anyah chhetta na upapadyate.' This is not flattery. It is the honest cry of a student who has tried every other source and come up empty. Only the teacher who sees the full picture can answer a question this deep.
The word 'chhetta' — one who cuts — carries the image of a sword slicing through a knot. Arjuna's doubt is tangled and tight. He needs it severed cleanly, not loosened partway.