Bhagavad Gita · Chapter 17: The Three Kinds of Faith

Bhagavad Gita 17.18

satkāramānapūjārthaṃ tapo dambhena caiva yat | kriyate tadiha proktaṃ rājasaṃ calamadhruvam ||

Austerity that is practised for show, in order to win respect, honour, and reverence, is said to be of passion. It is unsteady and does not last.

Modern context

Austerity done to win respect, honour and reverence is rajasic, and it is 'unsteady and does not last'. Discipline that depends on an audience collapses when the audience leaves. A person who fasts to be admired stops when no one is watching. Discipline that comes from within holds steady whether anyone notices or not.