deva-dvija-guru-prajna- pujanam shaucham arjavam। brahmacharyam ahimsa cha sariram tapa ucyate॥ 17.14 ॥

Sri Krishna said: O Arjuna, Austerity of the body consists in worship of the God, the Brahmins, the Spiritual master, and superiors like the father and mother, and in cleanliness, simplicity, celibacy and nonviolence.

anudvega-karam vakyam satyam priya-hitam cha yat। svadhyayabhyasanam chaiva van-mayam tapa ucyate॥ 17.15 ॥

Sri Krishna said: O Arjuna, Austerity of speech consists in speaking words that are truthful, pleasing, beneficial, and not agitating to others, and also in regularly reciting Vedic literature.

manah-prasadah saumyatvam maunam atma-vinigrahah। bhava-samsuddhir ity etat tapo manasam ucyate॥ 17.16 ॥

Sri Krishna said: O Arjuna, And satisfaction, simplicity, gravity, self-control and purification of one’s existence are the austerities of the mind.

shraddhaya paraya taptam tapas tat tri-vidham naraih। aphalakanksibhir yuktaih sattvikam parichakshate॥ 17.17 ॥

Sri Krishna said: O Arjuna, This threefold austerity, performed with transcendental faith by men not expecting material benefits but engaged only for the sake of the Supreme, is called austerity in goodness.