I am Time, grown mighty, the destroyer of the worlds, and I have set out here to gather in these worlds. Even without you, none of these warriors standing in the opposing ranks will survive.
Explanation
Arjuna has just seen Krishna's cosmic form and asked who this terrifying being is. Krishna answers that he is Time (kāla), the force that brings all worlds to their end. The warriors on the battlefield are already doomed by this force, whether or not Arjuna acts. Some commentators stress divine will and destiny here, while others stress that Arjuna must still choose to do his duty.