। ॥ २८० ॥
In plain words
Understand clearly: it is only the momentum of past action keeping this body going, nothing more. Stay unshaken by that fact. Hold onto your resolve, and with real effort, remove your own superimposition.
Close to the Sanskrit
Having ascertained that it is [only] prārabdha [karma] that sustains the body, [remaining] unmoved, holding fast to steadfastness, with effort, accomplish the removal of your own superimposition.