Bhagavad Gītā Chapter Four verse 40

ajñaścāśraddadhānaśca saṃśayātmā vinaśyati |
nāyaṃ loko ’sti na paro na sukhaṃ saṃśayātmanaḥ ||

saṃśaya - doubtātman - essence; the highest personal principle of lifesukha - pleasure; happiness; agreeable; ease; comfortable; pleasant

Commentaries and Reflections

T Krishnamacharya:

Saṃśaya is the Fire that consumes Wisdom.