yathaa pradeeptam jvalanam patangaa vishanti naashaaya samriddhavegaahaa |
tathaiva naashaaya vishanti lokaastavaapi vaktraani samriddhavegaahaa || 29 ||

Like moths enter a blazing fire with great speed for their destruction, so also do these people enter your mouths with great speed for their destruction.
yathaa : like
pradeeptam : blazing
jvalanam : fire
patangaahaa : moths
vishanti : enter
naashaaya : for destruction
samriddhavegaahaa : with great speed
tathaa : so do
eva : only
naashaaya : for destruction
vishanti : enter
lokaaha : these people
tava : your
api : also
vaktraani : mouths
samriddhavegaahaa : with great speed
In the previous shloka, Arjuna gave the example of rivers flowing into the ocean to indicate the ultimate dissolution of all names and forms back to their source, Ishvara. Some may raise a doubt here. They may say, water is inert so naturally it goes wherever the flow takes it. In order to dispel this doubt, Arjuna gives the example of moths that rush towards a flame, and are eventually destroyed. Sant Jnyaneshwar gives the example of water droplets evaporating on a hot iron rod in his commentary.
By showing the process of destruction at such a grand scale, Shri Krishna also wants to remove Arjuna’s fear of death. Since the physical body goes away after death, there is no question of pain once we die. We are scared not about the pain of death, but about losing all of our identity as a so-and so, with all his possessions and attachments. The name and form that we have become attached, and its network of relationships with other names and forms, is what ultimately gets dissolved.
But when we know that death is nothing but a return of our name and form into that of Ishvara’s, our fear of death will go away, or at least, diminish to a great extent. In fact, when we become a devotee of Ishvara, death loses its unpleasantness because now it means a return to the original source of the universe. We begin to lead our lives with a great degree of courage and fearlessness, because we know how it will all end.