B.G 17.18

सत्कारमानपूजार्थं तपो दम्भेन चैव यत्। क्रियते तदिह प्रोक्तं राजसं चलमध्रुवम् ॥१८॥

satkāramānapūjārthaṃ tapo dambhena caiva yat। kriyate tadih proktaṃ rājasaṃ calamadhruvam ॥18॥

[सत्कार (satkāra) - respect; मान (māna) - honor; पूजा (pūjā) - worship; अर्थम् (artham) - for the sake of; तपः (tapaḥ) - austerity; दम्भेन (dambhena) - with hypocrisy; च (ca) - and; एव (eva) - indeed; यत् (yat) - which; क्रियते (kriyate) - is performed; तत् (tat) - that; इह (iha) - here; प्रोक्तम् (proktam) - is said; राजसम् (rājasam) - in the mode of passion; चलम् (calam) - unstable; अध्रुवम् (adhruvam) - temporary;]

Austerity performed with the intent of gaining respect, honor, and worship, and done with hypocrisy, is considered to be 'rājasam' i.e. in the mode of passion, which is unstable and temporary.