As moths hurriedly rush into a blazing fire for (their own) destruction, so also these creatures hurriedly rush into Thy mouths for (their own) destruction.
In simple words
Arjuna uses another image: "Like moths racing toward a fire to their own destruction — these people are rushing into Your mouths to be destroyed."
Contemporary scholarly and practical interpretations for modern seekers.
This interpretation draws on a specific tradition and may not represent the view of any single school. For authoritative guidance within a specific tradition, seek a qualified teacher.
Modern
The unity between the unmanifest and the manifest creation is beautifully illustrated in the preceding verse through the analogy of rivers born from the ocean. All rivers, originating from the ocean, ultimately merge back into it. Yet no analogy is perfect in itself. The limitation in the river metaphor lies in this: because rivers lack consciousness, their merger with the ocean does not demonstrate conscious choice or will.
One might question whether conscious beings, endowed with independent discernment, would behave like insentient water. To demonstrate that all living creatures are compelled by their very nature toward the mouth of death, another illustration is offered: just as moths rush with great speed into the blazing fire of their own destruction. To Vyasa, all of nature itself appears as an open book of dharma. Through countless events and examples, he illuminates these fundamental truths: that the projection of the unmanifest into the manifest state is the process of creation, and the dissolution of the manifest back into its unmanifest form is destruction or death.
When we attempt to understand this seemingly terrible or demonic death from a true perspective, it sheds its disguise and reveals its serene and radiant countenance.
Arjuna's mental anguish arose primarily because he hastily made a flawed assessment of the great destruction that would occur on the battlefield of Kurukshetra. The sole remedy for his affliction was to elevate his vision to such a height that he could perceive and comprehend, in a single glance, this inevitable natural phenomenon of death. Sri Krishna provided him with precisely this remedy.
When any event is studied closely and thoroughly, the terrifying fangs of its venom lose their potency. Only when human discernment becomes clouded by ignorance do the events surrounding us strangle and overwhelm us. Just as rivers swiftly enter the ocean and moths rush into the mouth of fire, so too all forms dissolve into the unmanifest. When death is understood in this manner, one becomes free from fear and can face life courageously, for one's entire existence becomes an unbroken stream of transformation.
Therefore, death—as the play of time—becomes an event without its sting. In the verse that follows, this death is glorified in all its terrible beauty.