देहात्मधीरेव नृणामसद्धियांजन्मादिदुःखप्रभवस्य बीजम् ।यतस्ततस्त्वं जहि तां प्रयत्ना -त्त्यक्ते तु चित्ते न पुनर्भवाशा ॥ १६६ ॥
In plain words
This one idea -- that the body is the Self -- held by people of clouded intellect, is the very seed from which sprout birth and every sorrow that follows it. So, with real effort, uproot it. The moment the mind lets it go, there is no more prospect of being born again.
Close to the Sanskrit
The notion of the body as the Self, belonging to people of clouded intellect, is alone the seed of the origination of sorrow beginning with birth. Since this is so, therefore, destroy it by effort. When the mind has given it up, there is no more prospect of rebirth.